WorldWideScience

Sample records for driven sub-critical experiments

  1. Accelerator driven sub-critical core

    Science.gov (United States)

    McIntyre, Peter M; Sattarov, Akhdiyor

    2015-03-17

    Systems and methods for operating an accelerator driven sub-critical core. In one embodiment, a fission power generator includes a sub-critical core and a plurality of proton beam generators. Each of the proton beam generators is configured to concurrently provide a proton beam into a different area of the sub-critical core. Each proton beam scatters neutrons within the sub-critical core. The plurality of proton beam generators provides aggregate power to the sub-critical core, via the proton beams, to scatter neutrons sufficient to initiate fission in the sub-critical core.

  2. Nuclear data requirements for accelerator driven sub-critical systems

    Indian Academy of Sciences (India)

    The development of accelerator driven sub-critical systems (ADSS) require significant amount of new nuclear data in extended energy regions as well as for a variety of new materials. This paper reviews these perspectives in the Indian context.

  3. Reactor Dynamics Experiments with a Sub-Critical Assembly

    International Nuclear Information System (INIS)

    Miley, G.H.; Yang, Y.; Wu, L.; Momota, H.

    2004-01-01

    A resurgence in use of nuclear power is now underway worldwide. However due to the shutdown of many university research reactors , student laboratories must rely more heavily on use of sub-critical assemblies. Here a driven sub-critical is described that uses a cylindrical Inertial Electrostatic Confinement (IEC) device to provide a fusion neutron source. The small IEC neutron source would be inserted in a fuel element position, with its power input controlled externally at a control panel. This feature opens the way to use of the critical assembly for a number of transient experiments such as sub-critical pulsing and neutron wave propagation. That in turn adds important new insights and excitement for the student teaching laboratory

  4. International conference on sub-critical accelerator driven systems. Proceedings

    International Nuclear Information System (INIS)

    Litovkina, L.P.; Titarenko, Yu.E.

    1999-01-01

    The International Meeting on Sub-Critical Accelerator Driven Systems was organized by the State Scientific Center - Institute for Theoretical and Experimental Physics with participation of Atomic Ministry of RF. The Meeting objective was to analyze the recent achievements and tendencies of the accelerator-driven systems development. The Meeting program covers a broad range of problems including the accelerator-driven systems (ADS) conceptual design; analyzing the ADS role in nuclear fuel cycle; accuracy of modeling the main parameters of ADS; conceptual design of high-current accelerators. Moreover, the results of recent experimental and theoretical studies on nuclear data accumulation to support the ADS technologies are presented. About 70 scientists from the main scientific centers of Russia, as well as scientists from USA, France, Belgium, India, and Yugoslavia, attended the meeting and presented 44 works [ru

  5. Electron versus proton accelerator driven sub-critical system performance using TRIGA reactors at power

    International Nuclear Information System (INIS)

    Carta, M.; Burgio, N.; D'Angelo, A.; Santagata, A.; Petrovich, C.; Schikorr, M.; Beller, D.; Felice, L. S.; Imel, G.; Salvatores, M.

    2006-01-01

    This paper provides a comparison of the performance of an electron accelerator-driven experiment, under discussion within the Reactor Accelerator Coupling Experiments (RACE) Project, being conducted within the U.S. Dept. of Energy's Advanced Fuel Cycle Initiative (AFCI), and of the proton-driven experiment TRADE (TRIGA Accelerator Driven Experiment) originally planned at ENEA-Casaccia in Italy. Both experiments foresee the coupling to sub-critical TRIGA core configurations, and are aimed to investigate the relevant kinetic and dynamic accelerator-driven systems (ADS) core behavior characteristics in the presence of thermal reactivity feedback effects. TRADE was based on the coupling of an upgraded proton cyclotron, producing neutrons via spallation reactions on a tantalum (Ta) target, with the core driven at a maximum power around 200 kW. RACE is based on the coupling of an Electron Linac accelerator, producing neutrons via photoneutron reactions on a tungsten-copper (W-Cu) or uranium (U) target, with the core driven at a maximum power around 50 kW. The paper is focused on analysis of expected dynamic power response of the RACE core following reactivity and/or source transients. TRADE and RACE target-core power coupling coefficients are compared and discussed. (authors)

  6. The physics of accelerator driven sub-critical reactors

    Indian Academy of Sciences (India)

    Accelerator driven systems (ADS) are attracting worldwide attention .... The region of interest (or the entire reactor core) is divided into a suitable number ..... have also presented the status of the theoretical and experimental activities being.

  7. Burning of spent fuel of an accelerator-driven modular HTGR in sub-critical condition

    International Nuclear Information System (INIS)

    Jing Xingqing; Yang Yongwei; Chang Hong; Wu Zongxin; Gu Yuxiang

    2002-01-01

    The modular high temperature gas cooled reactor (MHTGR) has good safety characteristics because of the use of coated particles in the fuel element. After the particles cool outside of the reactor for some time, the spent fuel can be re-utilized. The author describes a physics feasibility study for the burning of spent fuel from a 350 MW ring-shaped modular high temperature gas cooled reactor in an accelerator-driven sub-critical reactor. A conceptual design is given for the 30 MW accelerator-driven sub-critical reactor. The neutron transport in the sub-critical reactor was simulated using the MCNP code, and the burnup was calculated using the ORIGEN2 code. The results show that the accelerator-driven sub-critical gas-cooled reactor has reliable sub-criticality and low power density and that the spent fuel from a 350 MW ring-shaped modular high temperature gas cooled reactor can be burned to provide 20% more energy

  8. Physics analyses of an accelerator-driven sub-critical assembly

    Science.gov (United States)

    Naberezhnev, Dmitry G.; Gohar, Yousry; Bailey, James; Belch, Henry

    2006-06-01

    Physics analyses have been performed for an accelerator-driven sub-critical assembly as a part of the Argonne National Laboratory activity in preparation for a joint conceptual design with the Kharkov Institute of Physics and Technology (KIPT) of Ukraine. KIPT has a plan to construct an accelerator-driven sub-critical assembly targeted towards the medical isotope production and the support of the Ukraine nuclear industry. The external neutron source is produced either through photonuclear reactions in tungsten or uranium targets, or deuteron reactions in a beryllium target. KIPT intends using the high-enriched uranium (HEU) for the fuel of the sub-critical assembly. The main objective of this paper is to study the possibility of utilizing low-enriched uranium (LEU) fuel instead of HEU fuel without penalizing the sub-critical assembly performance, in particular the neutron flux level. In the course of this activity, several studies have been carried out to investigate the main choices for the system's parameters. The external neutron source has been characterized and a pre-conceptual target design has been developed. Several sub-critical configurations with different fuel enrichments and densities have been considered. Based on our analysis, it was shown that the performance of the LEU fuel is comparable with that of the HEU fuel. The LEU fuel sub-critical assembly with 200-MeV electron energy and 100-kW electron beam power has an average total flux of ˜2.50×10 13 n/s cm 2 in the irradiation channels. The corresponding total facility power is ˜204 kW divided into 91 and 113 kW deposited in the target and sub-critical assemblies, respectively.

  9. Analysis on burn-up behaviors for accelerator-driven sub-critical facility

    International Nuclear Information System (INIS)

    Liu Guisheng; Zhao Zhixiang; Zhang Baocheng; Shen Qinbiao; Ding Dazhao

    2000-01-01

    An analysis is performed on burn-up behaviors for accelerator-driven sub-critical reactor by means of the code PASC-1 for neutronics calculation, the code CBURN for burn-up calculation and 44 group constants is processed by CENDL-2 and ENDF/B-6 using NJOY-91.91

  10. Conceptual research on reactor core physics for accelerator driven sub-critical reactor

    International Nuclear Information System (INIS)

    Zhao Zhixiang; Ding Dazhao; Liu Guisheng; Fan Sheng; Shen Qingbiao; Zhang Baocheng; Tian Ye

    2000-01-01

    The main properties of reactor core physics are analysed for accelerator driven sub-critical reactor. These properties include the breeding of fission nuclides, the condition of equilibrium, the accumulation of long-lived radioactive wastes, the effect from poison of fission products, as well as the thermal power output and the energy gain for sub-critical reactor. The comparison between thermal and fast system for main properties are carried out. The properties for a thermal-fast coupled system are also analysed

  11. Design status and future research programme for a sub-critical assembly driven by a proton accelerator with proton energy 660 MeV for experiments on long-lived fission products and minor actinides transmutation (Sad)

    International Nuclear Information System (INIS)

    Gustov, S.A.; Mirokhin, I.V.; Morozov, N.A.; Onischenko, L.M.; Savchenko, O.V.; Sissakian, A.N.; Shvetsov, V.N.; Tretyakov, I.T.; Lopatkin, A.V.; Vorontsov, M.T.

    2003-01-01

    Report presents project for the construction of a low power integral system on the basis of the proton accelerator of energy 660 MeV and sub-critical MOX blanket with uranium-plutonium fuel. Installation includes sub-critical core with a nominal thermal power of 15-20 kW. Multiplication coefficient k eff = 0,95 and the accelerator beam power of 0.75-1 kW. The experimental programme for SAD will be focused on solving different aspects of reactor physics, reaction rates measurements and benchmarking. The first conceptual design of the SAD experiment is completed in the form of the ISTC Project Proposal 2267. Realisation of the SAD facility may be expected in about 3-4 years. (author)

  12. Source-jerk method for application on ADS neutronics study The ADS is stated for Accelerator Driven sub-critical System

    CERN Document Server

    Zhu Qing Fu; Li Yi; Xia Pu; Zheng Wu Qing; Zhu Guo Sheng

    2003-01-01

    The paper is concerned in the source-jerk method used to measure the sub-criticality, and the sub-critical experiment facility, which is used for the study on the neutronics of ADS, driven by external neutron source sup 2 sup 5 sup 2 Cf. The effects of the location of neutron source and material buffer where is at the location of the pipe of proton beam and target of fission-product dispersion on the sub-criticality of reactor are studied by source-jerk method

  13. Calculation and analysis of burnup and optimum core design in accelerator driven sub-critical system

    International Nuclear Information System (INIS)

    Wang Yuwei; Yang Yongwei; Cui Pengfei

    2011-01-01

    The premise of the accelerator driven sub-critical system (ADS) in the accident is still subcritical, the biggest k eff change with burn time is less than 1.5% and the cladding material, HT9 steel, can withstand the maximum radiation damage, core fuel area is divided into fuel transmutation area and fuel multiplication area, and fuel transmutation area maintains the same fuel composition in the whole process. Through the analysis of the composition of the fuel, shape of core layout and the power distribution, etc., supposed outer and inner Pu enrichment ratio range of 1.0-1.5, then the fuel components of fuel multiplication area was adjusted. Time evolution of k eff was calculated by COUPLED2 which coupled with MCNP and ORIGEN. At the same time the power peaking factors, minoractinides transmutation rate desired to maximization and burnup were considered. A sub-critical system fitting for engineering practice was established. (authors)

  14. Reactor physics experiments in PURNIMA sub critical facility coupled with 14 MeV neutron source

    International Nuclear Information System (INIS)

    Kumar, Rajeev; Degweker, S.B.; Patel, Tarun; Bishnoi, Saroj; Adhikari, P.S.

    2011-01-01

    Accelerator Driven Sub-critical Systems (ADSS) are attracting increasing worldwide attention due to their superior safety characteristics and their potential for burning actinide and fission product waste and energy production. A number of countries around the world have drawn up roadmaps/programs for development of ADSS. Indian interest in ADSS has an additional dimension, which is related to the planned utilization of our large thorium reserves for future nuclear energy generation. A programme for development of ADSS is taken up at the Bhabha Atomic Research Centre (BARC) in India. This includes R and D activities for high current proton accelerator development, target development and Reactor Physics studies. As part of the ADSS Reactor Physics research programme, a sub-critical facility is coming up in BARC which will be coupled with an existing D-D/D-T neutron generator. Two types of cores are planned. In one of these, the sub-critical reactor assembly consists of natural uranium moderated by high density polyethylene (HDP) and reflected by BeO. The other consists of natural uranium moderated by light water. The maximum neutron yield of the neutron source with tritium target is around 10 10 neutron per sec. Various reactor physics experiments like measurement of the source strength, neutron flux distribution, buckling estimation and sub-critical source multiplication are planned. Apart from this, measurement of the total fission power and neutron spectrum will also be carried out. Mainly activation detectors will be used in all in-core neutron flux measurement. Measurement of the degree of sub-criticality by various deterministic and noise methods is planned. Helium detectors with advanced data acquisition card will be used for the neutron noise experiments. Noise characteristics of ADSS are expected to be different from that of traditional reactors due to the non-Poisson statistical features of the source. A new theory incorporating these features has been

  15. Journey from discovery of nuclear fission to accelerator-driven sub-critical reactor systems (ADS)

    International Nuclear Information System (INIS)

    Kapoor, S.S.

    2005-01-01

    The epoch making discovery of nuclear fission in 1939, which resulted purely from the curiosity driven basic research to understand the atomic and nuclear structure has changed the world forever with the onset of a new era in the history of human civilization. The basic nuclear physics research pursued after the discovery of fission has also been of much relevance in the harnessing of nuclear energy. In the recent years, there is considerable interest towards developing accelerator driven sub-critical reactor systems (ADS) for the incineration of the long-lived spent fuel radioactive waste and for the utilization of thorium fuel for nuclear power generation. In this talk, we discuss important milestones in the journey from discovery of nuclear fission to ADS. (author)

  16. 233U breeding in accelerator-driven sub-critical fast reactor

    International Nuclear Information System (INIS)

    Yang Yongwei; An Yu

    1999-01-01

    Accelerator-driven Sub-critical Fast Reactor (ADFR) is chosen as fissile-material-breeding reactor. (U-Pu)O x is chosen as fuel in the core and ThO 2 as fertile material in the blanket zone to breed 233 U. Molten lead is chosen as coolant because of its better neutronic and chemical characteristics over sodium. The program system used for neutronics study consists of: LAHET, for the simulation of the interaction between the proton with medium energy and the nuclei of the target; MCNP4A, for the simulation of neutron transport with energy below 20 MeV in the sub-critical reactor; CONNECT1, for the processing of some tallies provided by the output of MCNP4A in order to prepare micro-cross sections for elements used for burnup calculation; ORIGEN2, used for multi-region burnup calculation; CONNECT2, for the processing of atom densities of some elements provided in the output of ORIGEN2 in order to prepare input to LAHET calculation for next time step. The calculated results show that the proposed case is feasible for breeding fissile material considering the criticality safety, power density, burnup, etc

  17. Neutronic Design of an Accelerator Driven Sub-Critical Research Reactor

    International Nuclear Information System (INIS)

    Pesic, M.

    2002-01-01

    Conceptual design of an accelerator driven sub-critical research reactor (ADSRR), as a new project in the Vinca Institute of Nuclear Sciences, is suggested for support to the Ministry of science, technologies and development of Republic Serbia, Yugoslavia. This paper show initial results of neutronic analyses of the proposed ADSRR carried out by Monte Carlo based MCNP and SHIELD codes. According to the proposal, the ADSRR would be constructed, in a later phase, at high-energy channel H5B of the VINCY cyclotron of the TESLA Accelerator Installation, that is under completion in the Vinca Institute. The fuel elements of 80%-enriched uranium dioxide dispersed in aluminium matrix, available in the Vinca Institute, are proposed for the ADSRR core design. The HEU fuel elements are placed in aluminium tubes filled by the 'primary moderator' - light water. These 'fuel tubes' are placed in a square lattice within lead matrix in a stainless steel tank. The lead is used as a 'secondary moderator' in the core and as the axial and radial reflector. Such design of the ADSRR shows that this small low neutron flux system can be used as an experimental 'demonstration' ADS with some neutron characteristics similar to proposed well-known lead moderated and cooled power sub-critical ADS with intermediate or fast neutron spectrum. The proposed experimental ADSRR, beside usage as a valuable research machine in reactor and neutron physics, will contribute to following and developing new nuclear technologies in the country, useful for eventual nuclear power option and nuclear waste incineration in future. (author)

  18. Fusion-driven sub-critical dual-cooled waste transmutation blanket: design and analysis

    International Nuclear Information System (INIS)

    Wang Weihua; Wu Yican; Ke Yan; Kang Zhicheng; Wang Hongyan; Huang Qunying

    2003-01-01

    The Fusion-Driven Sub-critical System (FDS) is one of the Chinese programs to be further developed for fusion application. Its Dual-cooled Waste Transmutation Blanket (DWTB), as one the most important part of the FDS is cooled by helium and liquid metal, and have the features of safety, tritium self-sustaining, high efficiency and feasibility. Its conceptual design has been finished. This paper is mainly involved with the basic structure design and thermal-hydraulics analysis of DWTB. On the basis of a three-dimensional (3-D) model of radial-toroidal sections of the segment box, thermal temperature gradients and structure analysis made with a comprehensive finite element method (FEM) have been performed with the computer code ANSYS5.7 and computational fluid dynamic finite element codes. The analysis refers to the steady-state operating condition of an outboard blanket segment. Furthermore, the mechanical loads due to coolant pressure in normal operating conditions have been also taken into account. All the above loads have been combined as an input for a FEM stress analysis and the resulting stress distribution has been evaluated. Finally, the structure design and Pb-17Li flow velocity has been optimized according to the calculations and analysis

  19. Accelerator-driven sub-critical research facility with low-enriched fuel in lead matrix: Neutron flux calculation

    Directory of Open Access Journals (Sweden)

    Avramović Ivana

    2007-01-01

    Full Text Available The H5B is a concept of an accelerator-driven sub-critical research facility (ADSRF being developed over the last couple of years at the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. Using well-known computer codes, the MCNPX and MCNP, this paper deals with the results of a tar get study and neutron flux calculations in the sub-critical core. The neutron source is generated by an interaction of a proton or deuteron beam with the target placed inside the sub-critical core. The results of the total neutron flux density escaping the target and calculations of neutron yields for different target materials are also given here. Neutrons escaping the target volume with the group spectra (first step are used to specify a neutron source for further numerical simulations of the neutron flux density in the sub-critical core (second step. The results of the calculations of the neutron effective multiplication factor keff and neutron generation time L for the ADSRF model have also been presented. Neutron spectra calculations for an ADSRF with an uranium tar get (highest values of the neutron yield for the selected sub-critical core cells for both beams have also been presented in this paper.

  20. Sub-critical pulsed neutron experiments with uranyl nitrate solutions in spherical geometry

    International Nuclear Information System (INIS)

    Gurin, Victor N.; Ryazanov, Boris G.; Sviridov, Victor I.; Volnistov, Vladimir V.

    2003-01-01

    The pulse source method is used to study homogeneous solution assemblies. Three sets of sub-critical pulse experiments with spherical tanks filled with water solution of uranyl nitrate (90% enrichment) were carried out at the RF-GS facility, Obninsk, Russia. Seven spherical tanks with the volume within the range of 1.29 L to 19.8 L were used in the experiments. Three uranium concentrations were studied, i.e. 20.7, 29.6 and 37.5 g/L. The sub-critical experiments were analyzed with the MCNP 4A code based on the Monte-Carlo method, and with ENDF/B-V library. (author)

  1. Noise method for monitoring the sub-criticality in accelerator driven systems

    International Nuclear Information System (INIS)

    Rugama, Y.; Munoz-Cobo, J.L.; Valentine, T.E.; Mihalczo, J.T.; Perez, R.B.; Perez-Navarro, A.

    2001-01-01

    In this paper, an absolute measurements technique for the sub-criticality determination is presented. The development of ADS, requires of methods to monitor and control the sub-criticality of this kind of systems, without interfering it's normal operation mode. This method is based on the Stochastic Neutron and Photon Transport Theory developed by Munoz-Cobo et al., and which can be implemented in presently available neutron transport codes. As a by-product of the methodology a monitoring measurement technique has been developed and verified using two coupled Monte Carlo programs. The spallation collisions and the high-energy transport are simulated with LAHET. The neutrons transports with energies less than 20 MeV and the estimation of the count statistics for neutron and/or gamma ray counters in fissile systems, is simulated with MCNP-DSP. It is possible to get the kinetics parameters and the k eff value of the sub-critical system through the analysis of the counter detectors. (author)

  2. Critical and sub-critical experiments on U-BeO lattices

    International Nuclear Information System (INIS)

    Benoist, P.; Gourdon, Ch.; Martelly, J.; Sagot, M.; Wanner, G.

    1958-01-01

    Sub-critical experiments have allowed us to measure the material buckling of uranium natural oxide of beryllium lattices with a grid of 15 cm, and made up of uranium bars measuring 2.60 - 2.92 - 3.56 and 4.40 cm of diameter. A critical experiment has then been conducted with hollow 1.35 per cent enriched uranium bars. A study of U-BeO 18.03 cm grid lattices is at present being conducted. (author) [fr

  3. Neutronic design and analysis on dual-cooled waste transmutation blanket for the fusion driven sub-critical system

    International Nuclear Information System (INIS)

    Zheng Shanliang; Wu Yican; Gao Chunjing; Xu Dezheng; Li Jingjing; Zhu Xiaoxiang

    2004-01-01

    Neutronics design and analysis of dual-cooled multi-functional waste transmutation blanket (DWTB) for the fusion driven sub-critical system (FDS) are performed to ensure the system be able to meet the requirements of fuel-sufficiency and more waste transmutation ratio with low initial loading fuel inventory, which is based on 1-D burn-up calculations with home-developed code Visual BUS and the multi-group (175 neutron groups-42 Gamma groups coupled) data library HENDL1.0/MG (Hybrid Evaluated Nuclear Data Library). (authors)

  4. Accelerator-driven sub-critical target concept for transmutation of nuclear wastes

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Todosow, M.; Aronson, A.L.; Takahashi, H.; Geiger, M.J.

    1991-01-01

    A means of transmuting key long-lived nuclear wastes, primarily the minor actinides (Np, Am, Cm) and iodine, using a hybrid proton accelerator and sub-critical lattice, is proposed. By partitioning the components of the light water reactor (LWR) spent fuel and by transmuting key elements, such as the plutonium, the minor actinides, and a few of the long-lived fission products, some of the most significant challenges in building a waste repository can be substantially reduced. The proposed machine, based on the described PHOENIX Concept, would transmute the minor actinides and the iodine produced by 75 LWRs, and would generate usable electricity (beyond that required to run the large accelerator) of 850 MW e . 19 refs., 20 figs

  5. Reactor noise in critical and accelerator driven sub-critical systems

    International Nuclear Information System (INIS)

    Degweker, S.B.; Rana, Y.S.

    2007-01-01

    Noise methods have long been used for reactor kinetics parameters measurement and as diagnostic tools for monitoring the health of a nuclear power plant. It is conceivable that noise techniques would find similar applications in ADS. Measurement/monitoring the degree of sub-criticality of an ADS is one such application for which noise based methods are being considered, among others such as the pulsed source method. For this reason, theoretical studies on ADS noise have appeared since the late nineties. The principal difference between critical reactor noise and ADS noise is due to the statistical properties of the source. Unlike the source due to radioactive decay present in ordinary reactors, the machine produced ADS source cannot be assumed to be a Poisson process. In addition the source is pulsed. All this requires a new theoretical approach to the subject. In a number of papers (beginning in 2000) such a theoretical approach has been developed in BARC. Over the years, our approach has received general acceptance. The paper gives a description of the subject of reactor noise and its applications in critical reactors. The theory of noise in ADS is then outlined, highlighting the differences in approach and results from that of critical reactors. (author)

  6. Conceptual design for accelerator-driven sodium-cooled sub-critical transmutation reactors using scale laws

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Gu; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    The feasibility study on conceptual design methodology for accelerator-driven sodium-cooled sub-critical transmutation reactors has been conducted to optimize the design parameters from the scale laws and validates the reactor performance with the integrated code system. A 1000 MWth sodium-cooled sub-critical transmutation reactor has been scaled and verified through the methodology in this paper, which is referred to Advanced Liquid Metal Reactor (ALMR). A Pb-Bi target material and a partitioned fuel are the liquid phases, and they are cooled by the circulation of secondary Pb-Bi coolant and by primary sodium coolant, respectively. Overall key design parameters are generated from the scale laws and they are improved and validated by the integrated code system. Integrated Code System (ICS) consists of LAHET, HMCNP, ORIGEN2, and COMMIX codes and some files. Through ICS the target region, the core region, and thermal-hydraulic related regions are analyzed once-through Results of conceptual design are attached in this paper. 5 refs., 4 figs., 1 tab. (Author)

  7. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac.

    Science.gov (United States)

    Wu, Q; Ma, H Y; Yang, Y; Sun, L T; Zhang, X Z; Zhang, Z M; Zhao, H Y; He, Y; Zhao, H W

    2016-02-01

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  8. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    Science.gov (United States)

    Wu, Q.; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W.

    2016-02-01

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  9. Status of intense permanent magnet proton source for China-accelerator driven sub-critical system Linac

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Q., E-mail: wuq@impcas.ac.cn; Ma, H. Y.; Yang, Y.; Sun, L. T.; Zhang, X. Z.; Zhang, Z. M.; Zhao, H. Y.; He, Y.; Zhao, H. W. [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou 730000 (China)

    2016-02-15

    Two compact intense 2.45 GHz permanent magnet proton sources and their corresponding low energy beam transport (LEBT) system were developed successfully for China accelerator driven sub-critical system in 2014. Both the proton sources operate at 35 kV potential. The beams extracted from the ion source are transported by the LEBT, which is composed of two identical solenoids, to the 2.1 MeV Radio-Frequency Quadrupole (RFQ). In order to ensure the safety of the superconducting cavities during commissioning, an electrostatic-chopper has been designed and installed in the LEBT line that can chop the continuous wave beam into a pulsed one. The minimum width of the pulse is less than 10 μs and the fall/rise time of the chopper is about 20 ns. The performance of the proton source and the LEBT, such as beam current, beam profile, emittance and the impact to RFQ injection will be presented.

  10. Accelerator Driven Sub-Critical System for the Radioactive Waste Transmutation

    International Nuclear Information System (INIS)

    Avramovic, I.; Pesic, M.

    2008-01-01

    Spent nuclear fuel discharged from nuclear power plants is the main problem during design of radioactive waste disposal. Most of the hazard stems from only a few chemical elements. The radiotoxicity of these elements can be efficiently reduced using partitioning and transmutation in fast reactors and accelerator driven subcritical systems. (author)

  11. Experimental study on neutronics in bombardment of thick targets by high energy proton beams for accelerator-driven sub-critical system

    CERN Document Server

    Guo Shi Lun; Shi Yong Qian; Shen Qing Biao; Wan Jun Sheng; Brandt, R; Vater, P; Kulakov, B A; Krivopustov, M I; Sosnin, A N

    2002-01-01

    The experimental study on neutronics in the target region of accelerator-driven sub-critical system is carried out by using the high energy accelerator in Joint Institute for Nuclear Research, Dubna, Russia. The experiments with targets U(Pb), Pb and Hg bombarded by 0.533, 1.0, 3.7 and 7.4 GeV proton beams show that the neutron yield ratio of U(Pb) to Hg and Pb to Hg targets is (2.10 +- 0.10) and (1.76 +- 0.33), respectively. Hg target is disadvantageous to U(Pb) and Pb targets to get more neutrons. Neutron yield drops along 20 cm thick targets as the thickness penetrated by protons increases. The lower the energy of protons, the steeper the neutron yield drops. In order to get more uniform field of neutrons in the targets, the energy of protons from accelerators should not be lower than 1 GeV. The spectra of secondary neutrons produced by different energies of protons are similar, but the proportion of neutrons with higher energy gradually increases as the proton energy increases

  12. Neutronics optimization of LiPb-He dual-cooled fuel breeding blanket for the fusion-driven sub-critical system

    International Nuclear Information System (INIS)

    Zheng Shanliang; Wu Yican

    2002-01-01

    The concept of the liquid Li 17 Pb 83 and Helium gas dual-cooled Fuel Breeding Blanket (FBB) for the Fusion-Driven sub-critical System (FDS) is presented and analyzed. Taking self-sustaining tritium (TBR > 1.05) and annual output of 100 kg or more fissile 239 Pu (FBR > 0.238) as objective parameters, and based on the three-dimensional Monte Carlo neutron-photon transport code MCNP/4A, a neutronics-optimized calculation of different cases was carried out and the concept is proved feasible. In addition, the total breeding ratio (Br = Tbr + Fbr) is listed corresponding to different cases

  13. YALINA facility a sub-critical Accelerator- Driven System (ADS) for nuclear energy research facility description and an overview of the research program (1997-2008).

    Energy Technology Data Exchange (ETDEWEB)

    Gohar, Y.; Smith, D. L.; Nuclear Engineering Division

    2010-04-28

    The YALINA facility is a zero-power, sub-critical assembly driven by a conventional neutron generator. It was conceived, constructed, and put into operation at the Radiation Physics and Chemistry Problems Institute of the National Academy of Sciences of Belarus located in Minsk-Sosny, Belarus. This facility was conceived for the purpose of investigating the static and dynamic neutronics properties of accelerator driven sub-critical systems, and to serve as a neutron source for investigating the properties of nuclear reactions, in particular transmutation reactions involving minor-actinide nuclei. This report provides a detailed description of this facility and documents the progress of research carried out there during a period of approximately a decade since the facility was conceived and built until the end of 2008. During its history of development and operation to date (1997-2008), the YALINA facility has hosted several foreign groups that worked with the resident staff as collaborators. The participation of Argonne National Laboratory in the YALINA research programs commenced in 2005. For obvious reasons, special emphasis is placed in this report on the work at YALINA facility that has involved Argonne's participation. Attention is given here to the experimental program at YALINA facility as well as to analytical investigations aimed at validating codes and computational procedures and at providing a better understanding of the physics and operational behavior of the YALINA facility in particular, and ADS systems in general, during the period 1997-2008.

  14. A study of physics of sub-critical multiplicative systems driven by sources and the utilization of deterministic codes in calculation of this systems

    International Nuclear Information System (INIS)

    Antunes, Alberi

    2008-01-01

    This work presents the Physics of Source Driven Systems (ADS). It shows some statics and K i netics parameters of the reactor Physics and when it is sub critical, that are important in evaluation and definition of these systems. The objective is to demonstrate that there are differences in parameters when the reactor is critical. Moreover, the work shows the differences observed in the parameters for different calculation models. Two calculation methodologies are shown In this dissertation: Gandini and Salvatores and Dulla, and some parameters are calculated. The ANISN deterministic transport code is used in calculation in order to compare these parameters. In a subcritical configuration of IPEN-MB-01 Reactor driven by an external source some parameters are calculated. The conclusions about calculation realized are presented in end of work. (author)

  15. The mechanical design and fabrication of 162.5 MHz buncher for China accelerator driven sub-critical system injector II

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Hai Hua; Li, Youtang [Lanzhou University of Technology, Lanzhou (China); He, Yuan; Zhang, Bin; Huang, Shichun; Yuan, Chenzhang; Jia, Huan; Zhang, Shenghu [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou (China)

    2017-08-15

    A buncher is one of the main pieces of equipment in the medium energy beam transport line (MEBT) for China accelerator driven sub-critical system (C-ADS) Injector II. To focus the beam longitudinally and match the beam for the acceptance of the superconducting linac section, two room temperature quarter wave resonator (QWR) bunchers with frequency of 162.5 MHz have been designed as parts of the MEBT. According to the beam transmission matching of the MEBT and the geometric parameters requirements of bunchers, the unique mechanical structure and the main processing technology of buncher cavities and their couplers and tuners are described in this paper. The fabrication of bunchers and their parts have been completed and tested at high power, the test results agree well with the design requirements. These bunchers work well for about two years in Institute of Modern Physics, Chinese Academy of Sciences.

  16. The mechanical design and fabrication of 162.5 MHz buncher for China accelerator driven sub-critical system injector II

    Directory of Open Access Journals (Sweden)

    Haihua Niu

    2017-08-01

    Full Text Available A buncher is one of the main pieces of equipment in the medium energy beam transport line (MEBT for China accelerator driven sub-critical system (C-ADS Injector II. To focus the beam longitudinally and match the beam for the acceptance of the superconducting linac section, two room temperature quarter wave resonator (QWR bunchers with frequency of 162.5 MHz have been designed as parts of the MEBT. According to the beam transmission matching of the MEBT and the geometric parameters requirements of bunchers, the unique mechanical structure and the main processing technology of buncher cavities and their couplers and tuners are described in this paper. The fabrication of bunchers and their parts have been completed and tested at high power, the test results agree well with the design requirements. These bunchers work well for about two years in Institute of Modern Physics, Chinese Academy of Sciences.

  17. Design of a molten heavy-metal coolant and target for fast-thermal accelerator driven sub-critical system (ADS)

    International Nuclear Information System (INIS)

    Satyamurthy, P.; Degwekar, S.B.; Nema, P.K.

    2001-01-01

    Accelerator Driven sub-critical Systems (ADS) have evoked considerable interest in recent years. The Energy Amplifier concept developed by C. Rubbia and others at CERN incorporates a buoyancy driven, lead-coolant primary system for extracting the heat generated in the fast reactor as well as that in neutron spallation target. In earlier publications, our BARC group has proposed a one-way coupled booster reactor system which could be operated at proton beam currents as low as 1-2 mA for a power output of 750 MW th . Here, the basic idea is to have a fast booster reactor zone of low power (- 100 MW th ) which is separated by a large gap from the main thermal reactor zone. In this arrangement, the spallation neutron source feeds neutrons to the fast reactor zone where neutrons are further multiplied. Further in this system, the neutrons from the booster region enter the main reactor but very few neutrons from main reactor return to booster, thus ensuring one-way coupling. In earlier work, several possible configurations of the booster and thermal regions were presented. In the present work, we describe an engineering design particularly with respect to thermal hydraulics of lead/lead-bismuth eutectic coolant also acting as spallation neutron source. This hybrid ADS reactor consists of fast and thermal reactor zones producing about 100 MW th and 650 MW th respectively. The scheme of the system is shown. The fast core consists of 48 hexagonal fuel bundles each containing 169 fuel pins of 8.2 mm diameter arranged in 11.4 mm triangular array pitch. The average thermal power per fuel pin is about 13.46 kw. However, due to neutron flux peaking effect, the maximum fuel pin power can be up to 2.5 times this average power. The thermal reactor consists of heavy water as moderator and coolant similar to a typical CANDU type Indian PHWR except for fuel composition. Though the gap between fast and thermal zones essentially provides one way coupling of neutron flux, a thermal

  18. Critical and sub-critical experiments on U-BeO lattices; Experiences critiques et sous-critiques sur reseaux U-BeO

    Energy Technology Data Exchange (ETDEWEB)

    Benoist, P.; Gourdon, Ch.; Martelly, J.; Sagot, M.; Wanner, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Deniz, V.; Joshi, B.V.; Sahai, K. [Atomic Energy Establishment Trombay (India)

    1958-07-01

    Sub-critical experiments have allowed us to measure the material buckling of uranium natural oxide of beryllium lattices with a grid of 15 cm, and made up of uranium bars measuring 2.60 - 2.92 - 3.56 and 4.40 cm of diameter. A critical experiment has then been conducted with hollow 1.35 per cent enriched uranium bars. A study of U-BeO 18.03 cm grid lattices is at present being conducted. (author)Fren. [French] Nous avons mesure par des experiences sous-critiques le laplacien matiere de reseaux uranium naturel-oxyde de beryllium, dont la maille carree a un pas de 15 cm, realises avec des barreaux d'uranium de diametres 2,60 - 2,92 - 3,56 - 4,40 cm. Une experience critique a ete faite ensuite avec des barres creuses d'uranium enrichi a 1,35 pour cent; l'etude des reseaux U-BeO de pas 18,03 cm est actuellement en cours. (auteur)

  19. Critical and sub-critical experiments on U-BeO lattices; Experiences critiques et sous-critiques sur reseaux U-BeO

    Energy Technology Data Exchange (ETDEWEB)

    Benoist, P; Gourdon, Ch; Martelly, J; Sagot, M; Wanner, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Deniz, V; Joshi, B V; Sahai, K [Atomic Energy Establishment Trombay (India)

    1958-07-01

    Sub-critical experiments have allowed us to measure the material buckling of uranium natural oxide of beryllium lattices with a grid of 15 cm, and made up of uranium bars measuring 2.60 - 2.92 - 3.56 and 4.40 cm of diameter. A critical experiment has then been conducted with hollow 1.35 per cent enriched uranium bars. A study of U-BeO 18.03 cm grid lattices is at present being conducted. (author)Fren. [French] Nous avons mesure par des experiences sous-critiques le laplacien matiere de reseaux uranium naturel-oxyde de beryllium, dont la maille carree a un pas de 15 cm, realises avec des barreaux d'uranium de diametres 2,60 - 2,92 - 3,56 - 4,40 cm. Une experience critique a ete faite ensuite avec des barres creuses d'uranium enrichi a 1,35 pour cent; l'etude des reseaux U-BeO de pas 18,03 cm est actuellement en cours. (auteur)

  20. Sub-criticality monitoring for ADTR trademark control

    International Nuclear Information System (INIS)

    Ashworth, Roger

    2014-01-01

    Following the debut of the Accelerator Driven Thorium Reactor (ADTR trademark) Power Station at ENC 2010 in Barcelona, thorium as a reactor fuel has gained increasing support. The ADTR trademark concept reactor introduced the combination of an accelerator driven system (ADS) with traditional control rod technology, to provide a very high gain novel sub-critical ADS reactor design. The high gain of the system, while significantly reducing the demands on the accelerator design, pushes up operational sub-criticality (k eff ) closer to unity. In this paper we review this design and the progress made since ENC 2010. We compare 2 different methods of measuring the sub-critical neutron multiplication factor as the fuel cycle develops. The paper discusses the most recent work on k eff measurement and the interesting relationship between neutron flux, accelerator current and fuel temperature when using beam pulse methods to determine operational sub-criticality, of which a European patent is being granted. (orig.)

  1. Analysis of neutronics and dynamic characteristics with reactivity injection in LBE cooled sub-critical reactor

    International Nuclear Information System (INIS)

    Chen Sen; Wu Yican; Jin Ming; Chen Zhibin; Bai Yunqing; Zhao Zhumin

    2014-01-01

    Accelerator Driven Sub-critical System (ADS) has particular neutronics behaviors compared with the critical system. Prompt jump approximation point reactor kinetics equations taken external source into account have been deduced using an approach of prompt jump approximation. And the relationship between injection reactivity and power ampliation has been achieved. In addition, based on the RELAP5 code the prolong development of point reactor kinetics code used into assessing sub-critical system have been promoted. Different sub-criticality (k eff = 0.90, 0.95, 0.97, 0.98 and 0.99) have been assessed in preliminary design of a type of natural circulation cooling sub-critical reactor under conditions of reactivity injection +1 β in one second. It shows that the external source prompt transient approximation method has an accurate solution after injecting reactivity around short time and has a capacity to solve the dynamic equation, and the sub-critical system has an inner stability while the deeper sub-criticality the less impact on the sub-critical system. (authors)

  2. Laser driven hydrodynamic instability experiments

    International Nuclear Information System (INIS)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1993-01-01

    An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils allow a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes

  3. Kaliski's explosive driven fusion experiments

    International Nuclear Information System (INIS)

    Marshall, J.

    1979-01-01

    An experiment performed by a group in Poland on the production of DD fusion neutrons by purely explosive means is discussed. A method for multiplying shock velocities ordinarily available from high explosives by a factor of ten is described, and its application to DD fusion experiments is discussed

  4. Laser driven hydrodynamic instability experiments

    International Nuclear Information System (INIS)

    Remington, B.A.; Weber, S.V.; Haan, S.W.; Kilkenny, J.D.; Glendinning, S.G.; Wallace, R.J.; Goldstein, W.H.; Wilson, B.G.; Nash, J.K.

    1992-01-01

    We have conducted an extensive series of experiments on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime; multimode foils allow an assessment of the degree of mode coupling; and surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes. Experimental results and comparisons with theory and simulations are presented

  5. Modeling of laser-driven hydrodynamics experiments

    Science.gov (United States)

    di Stefano, Carlos; Doss, Forrest; Rasmus, Alex; Flippo, Kirk; Desjardins, Tiffany; Merritt, Elizabeth; Kline, John; Hager, Jon; Bradley, Paul

    2017-10-01

    Correct interpretation of hydrodynamics experiments driven by a laser-produced shock depends strongly on an understanding of the time-dependent effect of the irradiation conditions on the flow. In this talk, we discuss the modeling of such experiments using the RAGE radiation-hydrodynamics code. The focus is an instability experiment consisting of a period of relatively-steady shock conditions in which the Richtmyer-Meshkov process dominates, followed by a period of decaying flow conditions, in which the dominant growth process changes to Rayleigh-Taylor instability. The use of a laser model is essential for capturing the transition. also University of Michigan.

  6. Nuclear data requirements for accelerator driven sub-critical systems

    Indian Academy of Sciences (India)

    (b) Compilations coordinated by a classical data centre, computerized visual- izations, large data files information management, evaluations, that include nuclear model based predictions, creating ... and resources with a comprehensive approach to cover as many known ADSS de- signs as possible to meet the nuclear data ...

  7. Proposed sub-criticality level for an 80 MWTHd-bismuth-cooled Ads

    International Nuclear Information System (INIS)

    Mansani, L.; Monti, R.; Neuhold, P.

    2003-01-01

    The degree of operational sub-criticality of an Accelerator-driven System (ADS) on the one hand directly affects key accelerator system parameters, such as the proton beam current required to sustain the selected rated power level and, on the other, the likelihood of approaching or attaining criticality under abnormal or accident conditions. Then, if in all such conditions the safety goal is pursued to design the sub-critical core so that it stays away from criticality with adequate margin, the required operational sub-criticality level must be determined by a properly balanced approach between excessively demanding accelerator system performances and risk of accidental criticality. The approach must necessarily include evaluation and appropriate combination of the relevant reactivity effects (e.g. from system cool-down, postulated accident scenarios, geometrical variations) and proper consideration of specific design features (such as, for instance, the absence of safety rods, intended as neutron absorbing devices having a role equivalent to the shutdown rods in critical reactors). The paper presents a possible approach to the determination of the operational sub-criticality level of an 80 MWth Lead-Bismuth-cooled pool type ADS, initially conceived and developed by a team of Italian Organisations led by Ansaldo, with funding from the Ministry of University and Scientific and Technological Research, and currently in the process of being assessed, versus a gas-cooled concept, in the frame of a contract with the Commission of the European Communities. After a brief description of the Lead-Bismuth-cooled ADS concept relevant features and of the key safety goals in terms of required sub-criticality margin, the evaluated reactivity effects are presented, a method to combine them is discussed and a proposed operational sub-criticality level is derived. (author)

  8. Comparison of the transient behavior of lead-based advanced critical and sub-critical reactors

    International Nuclear Information System (INIS)

    Wang Gang; Gu Zhixing; Wang Zhen; Jin Ming; Bai Yunqing

    2014-01-01

    A lead-based reactor developed by FDS Team is proposed in 2011 and designed to be 10 MW. It is a pool type reactor and the primary coolant is driven by natural circulation. The reactor has two operation modes, which are a lead-based critical fast reactor mode and a lead-based sub-critical reactor mode. The conceptual designs of the two modes are both completed by 2013. In this paper, four transient accidents were simulated for both the critical and sub-critical reactors above by NTC-2D code, which is developed by FDS Team for advanced reactor safety analysis. The four accidents were protected and unprotected loss of heat sink accidents (PLOHS and ULOHS), protected and unprotected transient overpower accidents (PTOP and UTOP). The simulation results of the two reactors were compared and analyzed. The results showed that during PLOHS and PTOP accidents for both the two modes, all the key parameters (core power, fuel, cladding and coolant temperatures in the hottest channel) decreased to very small values after the reactor scrammed, which meant the reactors under the two modes were both safe. For ULOHS, the fuel, cladding and coolant temperatures of the sub-critical reactor increased bigger than those of the critical one. For UTOP, the parameters above of the critical fast reactor were much bigger than those of the sub-critical one. The analysis results showed different safety advantages of the lead-based critical fast and sub-critical reactors during different transient accidents. (author)

  9. Development of reactivity feedback effect measurement techniques under sub-critical condition in fast reactors

    International Nuclear Information System (INIS)

    Kitano, A.; Nishi, H.; Suzuki, T.; Okajima, S.; Kanemoto, S.

    2012-01-01

    The first-of-a-kind reactor has been licensed by a safety examination of the plant design based on the measured data in precedent mock-up experiments. The validity of the safety design can be confirmed without a mock-up experiment, if the reactor feed-back characteristics can be measured before operation, with the constructed reactor itself. The 'Synthesis Method', a systematic and sophisticated method of sub-criticality measurement, is proposed in this work to ensure the safety margin before operation. The 'Synthesis Method' is based on the modified source multiplication method (MSM) combined with the noise analysis method to measure the reference sub-criticality level for MSM. A numerical simulation for the control-rod reactivity worth and the isothermal feed-back reactivity was conducted for typical fast reactors of 100 MWe-size, 300 MWe-size, 750 MWe-size, and 1500 MWe-size to investigate the applicability of Synthesis Method. The number of neutron detectors and their positions necessary for the measurement were investigated for both methods of MSM and the noise analysis by a series of parametric survey calculations. As a result, it was suggested that a neutron detector located above the core center and three or more neutron detectors located above the radial blanket region enable the measurement of sub-criticality within 10% uncertainty from -$0.5 to -$2 and within 15% uncertainty for the deeper sub-criticality. (authors)

  10. Sub-Critical Nuclear Reactor Based on FFAG-Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Seok; Kang, Hung Sik; Lee, Tae Yeon [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)

    2011-10-15

    After the East-Japan earthquake and the subsequent nuclear disaster, the anti-nuclear mood has been wide spread. It is very unfortunate both for nuclear science community and for the future of mankind, which is threatened by two serious challenges, the global warming caused by the greenhouse effect and the shortage of energy cause by the petroleum exhaustion. While the nuclear energy seemed to be the only solution to these problems, it is clear that it has its own problems, one of which broke out so strikingly in Japan. There are also other problems such as the radiotoxic nuclear wastes that survive up to even tens of thousands years and the limited reserves of Uranium. To solve these problems of nuclear fission energy, accelerator-based sub-critical nuclear reactor was once proposed. (Its details will be explained below.) First of all, it is safe in a disaster such as an earthquake, because the deriving accelerator stops immediately by the earthquake. It also minimizes the nuclear waste problem by reducing the amount of the toxic waste and shortening their half lifetime to only a few hundred years. Finally, it solves the Uranium reserve problem because it can use Thorium as its fuel. The Thorium reserve is much larger than that of Uranium. Although the idea of the accelerator-driven nuclear reactor was proposed long time ago, it has not been utilized yet first by technical difficulty and economical reasons. The accelerator-based system needs 1 GeV, 10 MW power proton accelerator. A conventional linear accelerator would need several hundred m length, which is highly costly particularly in Korea because of the high land cost. However, recent technologies make it possible to realize that scale accelerator by a reasonable size. That is the fixed-field alternating gradient (FFAG) accelerator that is described in this article

  11. Sub-Critical Nuclear Reactor Based on FFAG-Accelerator

    International Nuclear Information System (INIS)

    Lee, Hee Seok; Kang, Hung Sik; Lee, Tae Yeon

    2011-01-01

    After the East-Japan earthquake and the subsequent nuclear disaster, the anti-nuclear mood has been wide spread. It is very unfortunate both for nuclear science community and for the future of mankind, which is threatened by two serious challenges, the global warming caused by the greenhouse effect and the shortage of energy cause by the petroleum exhaustion. While the nuclear energy seemed to be the only solution to these problems, it is clear that it has its own problems, one of which broke out so strikingly in Japan. There are also other problems such as the radiotoxic nuclear wastes that survive up to even tens of thousands years and the limited reserves of Uranium. To solve these problems of nuclear fission energy, accelerator-based sub-critical nuclear reactor was once proposed. (Its details will be explained below.) First of all, it is safe in a disaster such as an earthquake, because the deriving accelerator stops immediately by the earthquake. It also minimizes the nuclear waste problem by reducing the amount of the toxic waste and shortening their half lifetime to only a few hundred years. Finally, it solves the Uranium reserve problem because it can use Thorium as its fuel. The Thorium reserve is much larger than that of Uranium. Although the idea of the accelerator-driven nuclear reactor was proposed long time ago, it has not been utilized yet first by technical difficulty and economical reasons. The accelerator-based system needs 1 GeV, 10 MW power proton accelerator. A conventional linear accelerator would need several hundred m length, which is highly costly particularly in Korea because of the high land cost. However, recent technologies make it possible to realize that scale accelerator by a reasonable size. That is the fixed-field alternating gradient (FFAG) accelerator that is described in this article

  12. Towards a conceptual framework for Experience-Driven Innovation

    NARCIS (Netherlands)

    Schifferstein, H.N.J.; Kleinsmann, M.S.; Jepma, E.J.

    2012-01-01

    Companies that aim to evoke specific experiences among their customers, should not only modify their design process, but also need to reorganize their innovation processes. Experience-driven innovation has implications on at least three levels in the organization: company, brand, and product/service

  13. Driven reconnection in magnetic fusion experiments

    International Nuclear Information System (INIS)

    Fitzpatrick, R.

    1995-11-01

    Error fields (i.e. small non-axisymmetric perturbations of the magnetic field due to coil misalignments, etc.) are a fact of life in magnetic fusion experiments. What effects do error fields have on plasma confinement? How can any detrimental effects be alleviated? These, and other, questions are explored in detail in this lecture using simple resistive magnetohydrodynamic (resistance MHD) arguments. Although the lecture concentrates on one particular type of magnetic fusion device, namely, the tokamak, the analysis is fairly general and could also be used to examine the effects of error fields on other types of device (e.g. Reversed Field Pinches, Stellerators, etc.)

  14. Compression measurement in laser driven implosion experiments

    International Nuclear Information System (INIS)

    Attwood, D.T.; Cambell, E.M.; Ceglio, N.M.; Lane, S.L.; Larsen, J.T.; Matthews, D.M.

    1981-01-01

    This paper discusses the measurement of compression in the context of the Inertial Confinement Fusion Programs' transition from thin-walled exploding pusher targets, to thicker walled targets which are designed to lead the way towards ablative type implosions which will result in higher fuel density and pR at burn time. These experiments promote desirable reactor conditions but pose diagnostic problems because of reduced multi-kilovolt x-ray and reaction product emissions, as well as increasingly more difficult transport problems for these emissions as they pass through the thicker pR pusher conditions. Solutions to these problems, pointing the way toward higher energy twodimensional x-ray images, new reaction product imaging ideas and the use of seed gases for both x-ray spectroscopic and nuclear activation techniques are identified

  15. Electrically Driven Thermal Management: Flight Validation, Experiment Development, Future Technologies

    Science.gov (United States)

    Didion, Jeffrey R.

    2018-01-01

    Electrically Driven Thermal Management is an active research and technology development initiative incorporating ISS technology flight demonstrations (STP-H5), development of Microgravity Science Glovebox (MSG) flight experiment, and laboratory-based investigations of electrically based thermal management techniques. The program targets integrated thermal management for future generations of RF electronics and power electronic devices. This presentation reviews four program elements: i.) results from the Electrohydrodynamic (EHD) Long Term Flight Demonstration launched in February 2017 ii.) development of the Electrically Driven Liquid Film Boiling Experiment iii.) two University based research efforts iv.) development of Oscillating Heat Pipe evaluation at Goddard Space Flight Center.

  16. Consultancy on the potential of fusion/fission sub-critical neutron systems for energy production and transmutation. Working material

    International Nuclear Information System (INIS)

    2005-01-01

    The Workshop on Sub-critical Neutron Production held at the University of Maryland and the Eisenhower Institute on 11-13 October 2004 brought together members of fusion, fission and accelerator technical communities to discuss issues of spent fuel, nonproliferation, reactor safety and the use of neutrons for sub-critical operation of nuclear reactors. The Workshop strongly recommended that the fusion community work closely with other technical communities to ensure that a wider range of technical solutions is available to solve the spent fuel problem and to utilize the current actinide inventories. Participants of the Workshop recommended that a follow-on Workshop, possibly under the aegis of the IAEA, should be held in the first half of the year 2005. The Consultancy Meeting is the response to this recommendation. The objectives of the Consultancy meeting were to hold discussions on the role of fusion/fission systems in sub-critical operations of nuclear reactors. The participants agreed that development of innovative (fourth generation) fission reactors, advanced fuel cycle options, and disposition of existing spent nuclear fuel inventories in various Member Sates can significantly benefit from including sub-critical systems, which are driven by external neutron sources. Spallation neutrons produced by accelerators have been accepted in the past as the means of driving sub-critical reactors. The accelerator community deserves credit in pioneering this novel approach to reactor design. Progress in the design and operation of fusion devices now offers additional innovative means, broadening the range of sub-critical operations of fission reactors. Participants felt that fusion should participate with accelerators in providing a range of technical options in reactor design. Participants discussed concrete steps to set up a small fusion/fission system to demonstrate actinide burning in the laboratory and what advice should be given to the Agency on its role in

  17. Assessments of the kinetic and dynamic transient behavior of sub-critical systems (ADS) in comparison to critical reactor systems

    International Nuclear Information System (INIS)

    Schikorr, W.M.

    2001-01-01

    The neutron kinetic and the reactor dynamic behavior of Accelerator Driven Systems (ADS) is significantly different from those of conventional power reactor systems currently in use for the production of power. It is the objective of this study to examine and to demonstrate the intrinsic differences of the kinetic and dynamic behavior of accelerator driven systems to typical plant transient initiators in comparison to the known, kinetic and dynamic behavior of critical thermal and fast reactor systems. It will be shown that in sub-critical assemblies, changes in reactivity or in the external neutron source strength lead to an asymptotic power level essentially described by the instantaneous power change (i.e. prompt jump). Shutdown of ADS operating at high levels of sub-criticality, (i.e. k eff ∼0.99), without the support of reactivity control systems (such as control or safety rods), may be problematic in case the ability of cooling of the core should be impaired (i.e. loss of coolant flow). In addition, the dynamic behavior of sub-critical systems to typical plant transients such as protected or unprotected loss of flow (LOF) or heat sink (LOH) transients are not necessarily substantially different from the plant dynamic behavior of critical systems if the reactivity feedback coefficients of the ADS design are unfavorable. As expected, the state of sub-criticality and the temperature feedback coefficients, such as Doppler and coolant temperature coefficient, play dominant roles in determining the course and direction of plant transients. Should the combination of these safety coefficients be very unfavorable, not much additional margin in safety may be gained by making a critical system only sub-critical (i.e. k eff ∼0.95). A careful optimization procedure between the selected operating level of sub-criticality, the safety reactivity coefficients and the possible need for additional reactivity control systems seems, therefore, advisable during the early

  18. Demand-Driven Success: Designing Your PDA Experiment

    OpenAIRE

    Hillen, Charles; Johnson-Grau, Glenn

    2012-01-01

    Initiating demand-driving acquisition is daunting. Implications for developing a sustainable budget model, choosing a vendor, controlling metadata, monitoring purchases and developing invoice workflows are significant areas of concern that require determinative planning. From mid-February through August 2011, Loyola Marymount University conducted a pilot using demand-driven acquisition; the result of this successful experiment was the library’s decision to fully integrate this purchasing mode...

  19. Laser-driven ICF experiments: Laboratory Report No. 223

    International Nuclear Information System (INIS)

    McCrory, R.L.

    1991-04-01

    Laser irradiation uniformity is a key issue and is treated in some detail. The basic irradiation uniformity requirements and practical ways of achieving these requirements are both discussed, along with two beam-smoothing techniques: induced spatial incoherence (ISI), and smoothing by spectral dispersion (SSD). Experiments to measure and control the irradiation uniformity are also highlighted. Following the discussion of irradiation uniformity, a brief review of coronal physics is given, including the basic physical processes and their experimental signatures, together with a summary of pertinent diagnostics and results from experiments. Methods of determining ablation rates and thermal transport are also described. The hydrodynamics of laser-driven targets must be fully understood on the basis of experiments. Results from implosion experiments, including a brief description of the diagnostics, are presented. Future experiments aimed at determining ignition scaling and demonstrating hydrodynamically equivalent physics applicable to high-gain designs

  20. Locative media and data-driven computing experiments

    Directory of Open Access Journals (Sweden)

    Sung-Yueh Perng

    2016-06-01

    Full Text Available Over the past two decades urban social life has undergone a rapid and pervasive geocoding, becoming mediated, augmented and anticipated by location-sensitive technologies and services that generate and utilise big, personal, locative data. The production of these data has prompted the development of exploratory data-driven computing experiments that seek to find ways to extract value and insight from them. These projects often start from the data, rather than from a question or theory, and try to imagine and identify their potential utility. In this paper, we explore the desires and mechanics of data-driven computing experiments. We demonstrate how both locative media data and computing experiments are ‘staged’ to create new values and computing techniques, which in turn are used to try and derive possible futures that are ridden with unintended consequences. We argue that using computing experiments to imagine potential urban futures produces effects that often have little to do with creating new urban practices. Instead, these experiments promote Big Data science and the prospect that data produced for one purpose can be recast for another and act as alternative mechanisms of envisioning urban futures.

  1. Condensation during gravity driven ECC: Experiments with PACTEL

    Energy Technology Data Exchange (ETDEWEB)

    Munther, R.; Kalli, H. [Lappeenranta Univ. of Technology (Finland); Kouhia, J. [Technical Research Centre of Finland, Lappeenranta (Finland)

    1995-09-01

    This paper provides the results of the second series of gravity driven emergency core cooling (ECC) experiments with PACTEL (Parallel Channel Test Loop). The simulated accident was a small break loss-of-coolant accident (SBLOCA) with a break in a cold leg. The ECC flow was provided from a core makeup tank (CMT) located at a higher elevation than the main part of the primary system. The CMT was pressurized with pipings from the pressurizer and a cold leg. The tests indicated that steam condensation in the CMT can prevent ECC and lead to core uncovery.

  2. Transmutation of uranium and thorium in the particle field of the Quinta sub-critical assembly

    Science.gov (United States)

    Hashemi-Nezhad, S. R.; Asquith, N. L.; Voronko, V. A.; Sotnikov, V. V.; Zhadan, Alina; Zhuk, I. V.; Potapenko, A.; Husak, Krystsina; Chilap, V.; Adam, J.; Baldin, A.; Berlev, A.; Furman, W.; Kadykov, M.; Khushvaktov, J.; Kudashkin, I.; Mar'in, I.; Paraipan, M.; Pronskih, V.; Solnyshkin, A.; Tyutyunnikov, S.

    2018-03-01

    The fission rates of natural uranium and thorium were measured in the particle field of Quinta, a 512 kg natural uranium target-blanket sub-critical assembly. The Quinta assembly was irradiated with deuterons of energy 4 GeV from the Nuclotron accelerator of the Joint Institute for Nuclear Research (JINR), Dubna, Russia. Fission rates of uranium and thorium were measured using Gamma spectroscopy and fission track techniques. The production rate of 239Np was also measured. The obtained experimental results were compared with Monte Carlo predictions using the MCNPX 2.7 code employing the physics and fission-evaporation models of INCL4-ABLA, CEM03.03 and LAQGSM03.03. Some of the neutronic characteristics of the Quinta are compared with the "Energy plus Transmutation (EpT)" subcritical assembly, which is composed of a lead target and natU blanket. This comparison clearly demonstrates the importance of target material, neutron moderator and reflector types on the performance of a spallation neutron driven subcritical system. As the dimensions of the Quinta are very close to those of an optimal multi-rod-uranium target, the experimental and Monte Carlo calculation results presented in this paper provide insights on the particle field within a uranium target as well as in Accelerator Driven Systems in general.

  3. Consumer experiences in a consumer-driven health plan.

    Science.gov (United States)

    Christianson, Jon B; Parente, Stephen T; Feldman, Roger

    2004-08-01

    To assess the experience of enrollees in a consumer-driven health plan (CDHP). Survey of University of Minnesota employees regarding their 2002 health benefits. Comparison of regression-adjusted mean values for CDHP and other plan enrollees: customer service, plan paperwork, overall satisfaction, and plan switching. For CDHP enrollees only, use of plan features, willingness to recommend the plan to others, and reports of particularly negative or positive experiences. There were significant differences in experiences of CDHP enrollees versus enrollees in other plans with customer service and paperwork, but similar levels of satisfaction (on a 10-point scale) with health plans. Eight percent of CDHP enrollees left their plan after one year, compared to 5 percent of enrollees leaving other plans. A minority of CDHP enrollees used online plan features, but enrollees generally were satisfied with the amount and quality of the information provided by the CDHP. Almost half reported a particularly positive experience, compared to a quarter reporting a particularly negative experience. Thirty percent said they would recommend the plan to others, while an additional 57 percent said they would recommend it depending on the situation. Much more work is needed to determine how consumer experience varies with the number and type of plan options available, the design of the CDHP, and the length of time in the CDHP. Research also is needed on the factors that affect consumer decisions to leave CDHPs.

  4. Spike morphology in blast-wave-driven instability experiments

    International Nuclear Information System (INIS)

    Kuranz, C. C.; Drake, R. P.; Grosskopf, M. J.; Fryxell, B.; Budde, A.; Hansen, J. F.; Miles, A. R.; Plewa, T.; Hearn, N.; Knauer, J.

    2010-01-01

    The laboratory experiments described in the present paper observe the blast-wave-driven Rayleigh-Taylor instability with three-dimensional (3D) initial conditions. About 5 kJ of energy from the Omega laser creates conditions similar to those of the He-H interface during the explosion phase of a supernova. The experimental target is a 150 μm thick plastic disk followed by a low-density foam. The plastic piece has an embedded, 3D perturbation. The basic structure of the pattern is two orthogonal sine waves where each sine wave has an amplitude of 2.5 μm and a wavelength of 71 μm. In some experiments, an additional wavelength is added to explore the interaction of modes. In experiments with 3D initial conditions the spike morphology differs from what has been observed in other Rayleigh-Taylor experiments and simulations. Under certain conditions, experimental radiographs show some mass extending from the interface to the shock front. Current simulations show neither the spike morphology nor the spike penetration observed in the experiments. The amount of mass reaching the shock front is analyzed and potential causes for the spike morphology and the spikes reaching the shock are discussed. One such hypothesis is that these phenomena may be caused by magnetic pressure, generated by an azimuthal magnetic field produced by the plasma dynamics.

  5. Development of a plasma driven permeation experiment for TPE

    Energy Technology Data Exchange (ETDEWEB)

    Buchenauer, Dean, E-mail: dabuche@sandia.gov [Sandia National Laboratories, Livermore, CA (United States); Kolasinski, Robert [Sandia National Laboratories, Livermore, CA (United States); Shimada, Masa [Idaho National Laboratory, Idaho Falls, ID (United States); Donovan, David [Sandia National Laboratories, Livermore, CA (United States); Youchison, Dennis [Sandia National Laboratories, Albuquerque, NM (United States); Merrill, Brad [Idaho National Laboratory, Idaho Falls, ID (United States)

    2014-10-15

    Highlights: • We have designed and fabricated a novel tritium permeation membrane holder for use in the Tritium Plasma Experiment (TPE). • The membrane temperature is controlled by varying the cooling flow rate and proximity of a spiral cooling channel. • Sealing tests have demonstrated adequate helium leak rates up to temperatures of 1000 °C. • Flow modeling indicates a minimal helium pressure drop across the membrane holder (<700 Pa). • Thermal modeling shows good heat removal and minimal membrane temperature variation (±2%) even up to peak TPE ion fluxes. - Abstract: Experiments on retention of hydrogen isotopes (including tritium) at temperatures less than 800 °C have been carried out in the Tritium Plasma Experiment (TPE) at Idaho National Laboratory [1,2]. To provide a direct measurement of plasma driven permeation in plasma facing materials at temperatures reaching 1000 °C, a new TPE membrane holder has been built to hold test specimens (≤1 mm in thickness) at high temperature while measuring tritium permeating through the membrane from the plasma facing side. This measurement is accomplished by employing a carrier gas that transports the permeating tritium from the backside of the membrane to ion chambers giving a direct measurement of the plasma driven tritium permeation rate. Isolation of the membrane cooling and sweep gases from TPE's vacuum chamber has been demonstrated by sealing tests performed up to 1000 °C of a membrane holder design that provides easy change out of membrane specimens between tests. Simulations of the helium carrier gas which transports tritium to the ion chamber indicate a very small pressure drop (∼700 Pa) with good flow uniformity (at 1000 sccm). Thermal transport simulations indicate that temperatures up to 1000 °C are expected at the highest TPE fluxes.

  6. Development of a plasma driven permeation experiment for TPE

    International Nuclear Information System (INIS)

    Buchenauer, Dean; Kolasinski, Robert; Shimada, Masa; Donovan, David; Youchison, Dennis; Merrill, Brad

    2014-01-01

    Highlights: • We have designed and fabricated a novel tritium permeation membrane holder for use in the Tritium Plasma Experiment (TPE). • The membrane temperature is controlled by varying the cooling flow rate and proximity of a spiral cooling channel. • Sealing tests have demonstrated adequate helium leak rates up to temperatures of 1000 °C. • Flow modeling indicates a minimal helium pressure drop across the membrane holder (<700 Pa). • Thermal modeling shows good heat removal and minimal membrane temperature variation (±2%) even up to peak TPE ion fluxes. - Abstract: Experiments on retention of hydrogen isotopes (including tritium) at temperatures less than 800 °C have been carried out in the Tritium Plasma Experiment (TPE) at Idaho National Laboratory [1,2]. To provide a direct measurement of plasma driven permeation in plasma facing materials at temperatures reaching 1000 °C, a new TPE membrane holder has been built to hold test specimens (≤1 mm in thickness) at high temperature while measuring tritium permeating through the membrane from the plasma facing side. This measurement is accomplished by employing a carrier gas that transports the permeating tritium from the backside of the membrane to ion chambers giving a direct measurement of the plasma driven tritium permeation rate. Isolation of the membrane cooling and sweep gases from TPE's vacuum chamber has been demonstrated by sealing tests performed up to 1000 °C of a membrane holder design that provides easy change out of membrane specimens between tests. Simulations of the helium carrier gas which transports tritium to the ion chamber indicate a very small pressure drop (∼700 Pa) with good flow uniformity (at 1000 sccm). Thermal transport simulations indicate that temperatures up to 1000 °C are expected at the highest TPE fluxes

  7. Preliminary experiment research of explosively driven opening switch

    International Nuclear Information System (INIS)

    Li Xiaolin; Chen Dongqun; Li Da; Cao Shengguang; Chen Yingcong

    2010-01-01

    In pulse power technology field, many loads require high current pulse with fast risetime, but sometimes, the common high current pulse powers don't satisfy request, thus there need pulse erection switches of sorts to shorten pulse risetime. Explosively driven opening switch (EDOS) is a good choice, it has simple structure and excellent performance, the primary parameters of EDOS are opening time, opening resistance, opening current and dissipation energy, which determine its performance and range for applications. For this, two kinds of EDOS are designed and manufactured, in the later experiments, the power supply is a 200 μF capacitor and the conductor is 0.03 mm copper foil, the results indicate that the two kinds of EDOS have good performance, the opening time is about 1-3 μs, the opening resistance is about 1-2 Ω, the opening current is about 24-31 kA and the average dissipation energy is about 0.125-0.34 kJ per groove, the capability of conduction current is adjusted by the thickness of conductor along with different opening current. (authors)

  8. Accelerator-driven sub-critical reactor system (ADS) for nuclear ...

    Indian Academy of Sciences (India)

    High-energy accelerator; energy generation; radioactive waste elimination. PACS Nos 29.17. .... Withstands irradiation and thermal effects along with its container. (b) High-power proton ... That is, its availability is >99%. 946. Pramana – J.

  9. Towards a sufficiency-driven business model : Experiences and opportunities

    NARCIS (Netherlands)

    Bocken, N.M.P.; Short, SW

    2016-01-01

    Business model innovation is an important lever for change to tackle pressing sustainability issues. In this paper, ‘sufficiency’ is proposed as a driver of business model innovation for sustainability. Sufficiency-driven business models seek to moderate overall resource consumption by curbing

  10. Modelling of an experiment for the study of neutron spallation source at JINR

    International Nuclear Information System (INIS)

    Kumawat, Harphool; Goyal, Uttam; Kumar, V.; Barashenkov, V.S.

    2002-01-01

    Intense neutron spallation source (INSS) is a necessary requirement of accelerator driven sub-critical systems. INSS are proposed to be generated using the high current proton beams. Some studies are conducted for the neutron flux, transmutation rates and energy gains and a larger number of related experiments are being planned

  11. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    CERN Document Server

    Gschwendtner, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V.K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P.N.; Burt, G.; Buttenschon, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A.A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Huther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K.V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V.A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Oz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z.M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A.P.; Spitsyn, R.I.; Trines, R.; Tuev, P.V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C.P.; Wing, M.; Xia, G.; Zhang, H.

    2016-01-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected to sample the wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  12. Treatment of radioactive ionic exchange resins by super- and sub-critical water oxidation (SCWO)

    International Nuclear Information System (INIS)

    Kim, Kyeongsook; Son, Soon Hwan; Kim, Kwang Sin; Han, Joo Hee; Han, Kee Do; Do, Seung Hoe

    2010-01-01

    As the usage of ion exchange resins increases the inventory of spent ion exchange resins increases in nuclear power plants. This study is to find an environmental-friendly process to treat theses spent resins. The test samples were prepared by diluting the slurry made by wet ball milling the spent cationic exchange resins for 24 h. The spent cationic exchange resins were separated from mixed ion exchange resins by a fluidized bed gravimetric separator. The decomposition of the samples was investigated with super-critical water oxidation (SCWO) equipment. A statistical test method - the central composite design as a statistical design of experiments - was adopted to find the optimum condition to decompose the spent exchange resins. The optimum condition was 60% of excess oxygen, 22.5 min of residence time, 0.615 wt% of NaOH, 358 of reaction temperature, and 3600 psi of reaction pressure, which is a sub-critical condition. The liquid product of the decomposition has the characteristics of 80-185 ppm of COD (Chemical Oxygen Demand), 4.0-6.0 of pH, and <1.0 ppm of corrosive components (Ni, Fe, Cr, and Mo). The exhaust gas from the SCWO equipment contained NOx of 0 ppm, SOx of 3 ppm (environment exhaust standard in Korea: NOx 200 ppm, SOx 300 ppm). Co-substituted mock samples were prepared to simulate spent cationic exchange resins from nuclear power plants which can contain radioactive Co isotopes. The conditions to obtain organic compound destruction ratio which conforms the effluent stand for the mock samples were found. The treated water filtered with 0.2-filter contained less than 1 ppm of Co. Thus Co recovery rate of more 99% was achieved.

  13. Recovery of Organic and Amino Acids from Sludge and Fish Waste in Sub Critical Water Conditions

    Directory of Open Access Journals (Sweden)

    Muhammad Faisal

    2011-12-01

    Full Text Available The possibility of organic and amino acid production from the treatment of sludge and fish waste using water at sub critical conditions was investigated. The results indicated that at sub-critical conditions, where the ion product of water went through a maximum, the formation of organic acids was favorable. The presence of oxidant favored formation of acetic and formic acid. Other organic acids of significant amount were propionic, succinic and lactic acids. Depending on the type of wastes, formation of other organic acids was also possible. Knowing the organic acids obtained by hydrolysis and oxidation in sub-critical water of various wastes are useful in designing of applicable waste treatment process, complete degradation of organic wastes into volatile carbon and water, and also on the viewpoint of resource recovery. The production of lactic acid was discussed as well. The results indicated that temperature of 573 K, with the absence of oxidant, yield of lactic acid from fish waste was higher than sewage sludge. The maximum yield of total amino acids (137 mg/g-dry fish from waste fish entrails was obtained at subcritical condition (T = 523 K, P = 4 MPa at reaction time of 60 min by using the batch reactor. The amino acids obtained in this study were mainly alanine and glycine. Keywords:  organic acids, amino acids, sub-critical water, hydrothermal, resources recovery

  14. Radiological Impact of the TRIGA Accelerator-Driven Experiment (TRADE)

    CERN Document Server

    Herrera-Martínez, A; Kadi, Y; Zanini, L; Parks, G T; Rubbia, Carlo; Burgio, N; Carta, M; Santagata, A; Cinotti, L

    2002-01-01

    The TRADE project, which is part of the European Roadmap towards the development of Accelerator Driven Systems (ADS), foresees the coupling of a 110 MeV, 2 mA proton cyclotron with the core of a 1 MW Triga research reactor. We performed radioprotection studies using two state-of-the-art computer code packages, FLUKA and EA-MC. We concentrated on the calculation of the neutron and particle flux and dose rates during normal operation as well as in the case of several possible accidents, in order to assess the radiation damage and define the design of key components of the facility, such as the beam-line shielding. Both high-energy particle interactions and low-energy neutron transport are treated with a sophisticated method based on a full Monte Carlo simulation, combined with the use of modern nuclear data libraries.

  15. Progress in heavy ion driven inertial fusion energy: From scaled experiments to the integrated research experiment

    International Nuclear Information System (INIS)

    Barnard, J.J.; Ahle, L.E.; Baca, D.; Bangerter, R.O.; Bieniosek, F.M.; Celata, C.M.; Chacon-Golcher, E.; Davidson, R.C.; Faltens, A.; Friedman, A.; Franks, R.M.; Grote, D.P.; Haber, I.; Henestroza, E.; Hoon, M.J.L. de; Kaganovich, I.; Karpenko, V.P.; Kishek, R.A.; Kwan, J.W.; Lee, E.P.; Logan, B.G.; Lund, S.M.; Meier, W.R.; Molvik, A.W.; Olson, C.; Prost, L.R.; Qin, H.; Rose, D.; Sabbi, G.-L.; Sangster, T.C.; Seidl, P.A.; Sharp, W.M.; Shuman, D.; Vay, J.-L.; Waldron, W.L.; Welch, D.; Yu, S.S.

    2001-01-01

    The promise of inertial fusion energy driven by heavy ion beams requires the development of accelerators that produce ion currents (∼100's Amperes/beam) and ion energies (∼1-10 GeV) that have not been achieved simultaneously in any existing accelerator. The high currents imply high generalized perveances, large tune depressions, and high space charge potentials of the beam center relative to the beam pipe. Many of the scientific issues associated with ion beams of high perveance and large tune depression have been addressed over the last two decades on scaled experiments at Lawrence Berkeley and Lawrence Livermore National Laboratories, the University of Maryland, and elsewhere. The additional requirement of high space charge potential (or equivalently high line charge density) gives rise to effects (particularly the role of electrons in beam transport) which must be understood before proceeding to a large scale accelerator. The first phase of a new series of experiments in Heavy Ion Fusion Virtual National Laboratory (HIF VNL), the High Current Experiments (HCX), is now being constructed at LBNL. The mission of the HCX will be to transport beams with driver line charge density so as to investigate the physics of this regime, including constraints on the maximum radial filling factor of the beam through the pipe. This factor is important for determining both cost and reliability of a driver scale accelerator. The HCX will provide data for design of the next steps in the sequence of experiments leading to an inertial fusion energy power plant. The focus of the program after the HCX will be on integration of all of the manipulations required for a driver. In the near term following HCX, an Integrated Beam Experiment (IBX) of the same general scale as the HCX is envisioned. The step which bridges the gap between the IBX and an engineering test facility for fusion has been designated the Integrated Research Experiment (IRE). The IRE (like the IBX) will provide an

  16. Data driven processor 'Vertex Trigger' for B experiments

    International Nuclear Information System (INIS)

    Hartouni, E.P.

    1993-01-01

    Data Driven Processors (DDP's) are specialized computation engines configured to solve specific numerical problems, such as vertex reconstruction. The architecture of the DDP which is the subject of this talk was designed and implemented by W. Sippach and B.C. Knapp at Nevis Lab. in the early 1980's. This particular implementation allows multiple parallel streams of data to provide input to a heterogenous collection of simple operators whose interconnection form an algorithm. The local data flow control allows this device to execute algorithms extremely quickly provided that care is taken in the layout of the algorithm. I/O rates of several hundred megabytes/second are routinely achieved thus making DDP's attractive candidates for complex online calculations. The original question was open-quote can a DDP reconstruct tracks in a Silicon Vertex Detector, find events with a separated vertex and do it fast enough to be used as an online trigger?close-quote Restating this inquiry as three questions and describing the answers to the questions will be the subject of this talk. The three specific questions are: (1) Can an algorithm be found which reconstructs tracks in a planar geometry and no magnetic field; (2) Can separated vertices be recognized in some way; (3) Can the algorithm be implemented in the Nevis-UMass and DDP and execute in 10-20 μs?

  17. Gravity driven emergency core cooling experiments with the PACTEL facility

    International Nuclear Information System (INIS)

    Munther, R.; Kalli, H.; Kouhia, J.

    1996-01-01

    PACTEL (Parallel Channel Test Loop) is an experimental out-of-pile facility designed to simulated the major components and system behaviour of a commercial Pressurized Water Reactor (PWR) during different postulated LOCAs and transients. The reference reactor to the PACTEL facility is Loviisa type WWER-440. The recently made modifications enable experiments to be conducted also on the passive core cooling. In these experiments the passive core cooling system consisted of one core makeup tank (CMT) and pressure balancing lines from the pressurizer and from a cold leg connected to the top of the CMT in order to maintain the tank in pressure equilibrium with the primary system during ECC injection. The line from the pressurizer to the core makeup tank was normally open. The ECC flow was provided from the CMT located at a higher elevation than the main part of the primary system. A total number of nine experiments have been performed by now. 4 refs, 7 figs, 3 tabs

  18. Gravity driven emergency core cooling experiments with the PACTEL facility

    Energy Technology Data Exchange (ETDEWEB)

    Munther, R; Kalli, H [University of Technology, Lappeenranta (Finland); Kouhia, J [Technical Research Centre of Finland, Lappeenranta (Finland)

    1996-12-01

    PACTEL (Parallel Channel Test Loop) is an experimental out-of-pile facility designed to simulated the major components and system behaviour of a commercial Pressurized Water Reactor (PWR) during different postulated LOCAs and transients. The reference reactor to the PACTEL facility is Loviisa type WWER-440. The recently made modifications enable experiments to be conducted also on the passive core cooling. In these experiments the passive core cooling system consisted of one core makeup tank (CMT) and pressure balancing lines from the pressurizer and from a cold leg connected to the top of the CMT in order to maintain the tank in pressure equilibrium with the primary system during ECC injection. The line from the pressurizer to the core makeup tank was normally open. The ECC flow was provided from the CMT located at a higher elevation than the main part of the primary system. A total number of nine experiments have been performed by now. 4 refs, 7 figs, 3 tabs.

  19. New piezo driven gas inlet valve for fusion experiments

    International Nuclear Information System (INIS)

    Usselmann, E.; Hemmerich, J.L.; How, J.; Holland, D.; Orchard, J.; Winkel, T.; Schargitz, U.; Pocheim, N.

    1989-01-01

    The gas inlet valves used at the JET experiment are described and their performances are discussed. A new gas-valve development suitable to replace the existing valves at JET and for future use in large fusion experiments is presented. The new valve is equipped with a piezo-electric translator and has a dosing range of 0-800 mbarls -1 for D 2 . The operating mode of the valve is fail-safe closed with a leak-rate of ≤ 10 -9 mbarls -1 . The design, the test results and throughput values in dependence of filling pressure and control voltage are presented and experiences with the prototype valve as a new gas inlet valve for the JET operation are described

  20. Libration-Driven Elliptical Instability Experiments in Ellipsoidal Shells

    Science.gov (United States)

    Grannan, A. M.; Lemasquerier, D. G.; Favier, B.; Cebron, D.; Le Bars, M.; Aurnou, J. M.

    2016-12-01

    Planets and satellites can be subjected to physical libration, which consists in forced periodic variations in their rotation rate induced by gravitational interactions with nearby bodies. These librations may mechanically drive turbulence in interior liquid layers such as subsurface oceans and metallic liquid cores. One possible driving-process is called the Libration-Driven Elliptical Instability (LDEI) and refers to the resonance of two inertial modes with the libration induced base flow. LDEI has been experimentally and numerically studied in the case of a full ellipsoid (e.g. Cébron et al. [2012c], Grannan et al. [2014] and Favier et al. [2015]). In this study, we address the question of the persistence of the LDEI in the theoretically complex case of an ellipsoidal shell which is more geophysically relevant to model planetary liquid layers. We use an ellipsoidal acrylic container filled with water and add spherical inner cores of different sizes. We perform direct side-view visualizations of the flow in the librating frame using Kalliroscope particles. A Fourier analysis of the light intensity extracted from the recorded movies shows that LDEI persists in a shell geometry for a libration frequency which is 4 and 2.4 time the rotation rate, and allows an identification of the mode coupling. Particle Image Velocimetry (PIV) is performed in vertical and horizontal planes on a selected case to confirm our light intensity results. Additionaly, our survey at a fixed forcing-frequency and variable Ekman number (E) allows a comparison with a local stability analysis, and shows that the libration amplitude at the threshold of the instability varies as ≈[E0.63, E0.72]. When extrapolating to planetary interiors conditions, such a scaling leads to an easier excitation of the elliptical instability than the E0.5 scaling commonly considered.

  1. Application of the modified neutron source multiplication method for a measurement of sub-criticality in AGN-201K reactor

    International Nuclear Information System (INIS)

    Myung-Hyun Kim

    2010-01-01

    Measurement of sub-criticality is a challenging and required task in nuclear industry both for nuclear criticality safety and physics test in nuclear power plant. A relatively new method named as Modified Neutron Source Multiplication Method (MNSM) was proposed in Japan. This method is an improvement of traditional Neutron Source Multiplication (NSM) Method, in which three correction factors are applied additionally. In this study, MNSM was tested in calculation of rod worth using an educational reactor in Kyung Hee University, AGN-201K. For this study, a revised nuclear data library and a neutron transport code system TRANSX-PARTISN were used for the calculation of correction factors for various control rod positions and source locations. Experiments were designed and performed to enhance errors in NSM from the location effects of source and detectors. MNSM can correct these effects but current results showed not much correction effects. (author)

  2. Understanding hospital meal experiences by means of Participant-Driven-Photo-Elicitation

    DEFF Research Database (Denmark)

    Justesen, Lise; Mikkelsen, Bent Egberg; Gyimóthy, Szilvia

    2014-01-01

    A patients’ hospital meal experiences can be complex and often difficult to capture using traditional methods. This study investigated patients’ hospital meal experiences using participant-driven-photo-elicitation (PDPE). PDPE invites respondents to photograph their daily lives and combines this ...

  3. DIAGNOSTICS FOR ION BEAM DRIVEN HIGH ENERGY DENSITY PHYSICS EXPERIMENTS

    International Nuclear Information System (INIS)

    Bieniosek, F.M.; Henestroza, E.; Lidia, S.; Ni, P.A.

    2010-01-01

    Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ion beam accelerator. The 0.3 MeV, 30-mA K + beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ion beam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multi-channel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (VISAR), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II.

  4. Induction linac driven relativistic klystron and cyclotron autoresonance maser experiments

    International Nuclear Information System (INIS)

    Goodman, D.L.; Birx, D.L.; Danly, B.G.

    1991-01-01

    In this paper design and experimental results are presented from two high power microwave generation experiments utilizing a high repetition rate induction linac generated electron beam. A relativistic klystron has generated more than 100 MW microwave pulses in X-band for 50 ns without pulse shortening or breakdown. design studies for the first cyclotron autoresonance maser (CARM) amplifier using an induction linac electron beam are also presented

  5. Quick-fire: Plasma flow driven implosion experiments

    International Nuclear Information System (INIS)

    Baker, W.L.; Bigelow, W.S.; Degnan, J.H.

    1985-01-01

    High speed plasma implosions involving megajoules of energy, and sub-microsecond implosion times are expected to require additional stages of power conditioning between realistic primary energy sources and the implosion system. Plasma flow switches and vacuum inductive stores represent attractive alternates to the high speed fuse and atmospheric store techniques which have been previously reported for powering such plasma experiments. In experiments being conducted at the Air Force Weapons Lab, a washer shaped plasma accelerated to 7-10 cm/microsecond in a coaxial plasma gun configuration, represents the moving element in a vacuum store/power conditioning system of 16.5 nH inductance which stores 1-1.5 MJ at 12-14 MA. At the end of the coaxial gun, the moving element transits the 2cm axial length of the cylindrical implosion gap in 200-400 nS, delivering the magnetic energy to the implosion foil, accelerating the imploding plasma to speeds of 30-40 cm/microsecond in 350-450 nS, and delivering a projected 400 KJ of kinetic energy to the implosion. Experiments have been conducted using the SHIVA STAR capacitor bank operating at 6 MJ stored energy in which performance has been monitored by electrical diagnostics, magnetic probes, and axial and radial viewing high speed visible and X-Ray photographs to assess the performance of the coaxial run and coaxial to radial transition. Time and spectrally resolved X-Ray diagnostics are used to assess implosion quality and performance and results are compared to kinematic and MHD models

  6. QUICK-FIRE: Plasma flow driven implosion experiments

    International Nuclear Information System (INIS)

    Baker, W.L.; Bigelow, W.S.; Degnan, J.H.

    1985-01-01

    High speed plasma implosions involving megajoules of energy, and sub-microsecond implosion times are expected to require additional stages of power conditioning between realistic primary energy sources and the implosion system. Plasma flow switches and vacuum inductive stores represent attractive alternates to the high speed fuse and atmospheric store techniques which have been previously reported for powering such plasma experiments. In experiments being conducted at the Air Force Weapons Lab, a washer shaped plasma accelerated to 7-10 cm/microsecond in a coaxial plasma gun configuration, represents the moving element in a vacuum store/power conditioning system of 16.5 nH inductance which stores 1-1.5 MJ at 12-14 MA. At the end of the coaxial gun, the moving element transits the 2cm axial length of the cylindrical implosion gap in 200-400 nS, delivering the magnetic energy to the implosion foil, accelerating the imploding plasma to speeds of 30-40 cm/microsecond in 350-450 nS, and delivering a projected 400 KJ of kinetic energy to the implosion

  7. Semantics-Driven Migration of Java Programs: a Practical Experience

    Directory of Open Access Journals (Sweden)

    Artyom O. Aleksyuk

    2017-01-01

    Full Text Available The purpose of the study is to demonstrate the feasibility of automated code migration to a new set of programming libraries. Code migration is a common task in modern software projects. For example, it may arise when a project should be ported to a more secure or feature-rich library, a new platform or a new version of an already used library. The developed method and tool are based on the previously created by the authors a formalism for describing libraries semantics. The formalism specifies a library behaviour by using a system of extended finite state machines (EFSM. This paper outlines the metamodel designed to specify library descriptions and proposes an easy to use domainspecific language (DSL, which can be used to define models for particular libraries. The mentioned metamodel directly forms the code migration procedure. A process of migration is split into five steps, and each step is also described in the paper. The procedure uses an algorithm based on the breadth- first search extended for the needs of the migration task. Models and algorithms were implemented in the prototype of an automated code migration tool. The prototype was tested by both artificial code examples and a real-world open source project. The article describes the experiments performed, the difficulties that have arisen in the process of migration of test samples, and how they are solved in the proposed procedure. The results of experiments indicate that code migration can be successfully automated. 

  8. Uranium Enrichment Determination of the InSTEC Sub Critical Ensemble Fuel by Gamma Spectrometry

    International Nuclear Information System (INIS)

    Borrell Munnoz, Jose L.; LopezPino, Neivy; Diaz Rizo, Oscar; D'Alessandro Rodriguez, Katia; Padilla Cabal, Fatima; Arbelo Penna, Yunieski; Garcia Rios, Aczel R.; Quintas Munn, Ernesto L.; Casanova Diaz, Amaya O.

    2009-01-01

    Low background gamma spectrometry was applied to analyze the uranium enrichment of the nuclear fuel used in the InSTEC Sub Critical ensemble. The enrichment was calculated by two variants: an absolute method using the Monte Carlo method to simulated detector volumetric efficiency, and an iterative procedure without using standard sources. The results confirm that the nuclear fuel of the ensemble is natural uranium without any additional degree of enrichment. (author)

  9. Analytical solution of point kinetic equations for sub-critical systems

    International Nuclear Information System (INIS)

    Henrice Junior, Edson; Goncalves, Alessandro C.

    2013-01-01

    This article presents an analytical solution for the set of point kinetic equations for sub-critical reactors. This solution stems from the ordinary, non-homogeneous differential equation that rules the neutron density and that presents the incomplete Gamma function in its functional form. The method used proved advantageous and allowed practical applications such as the linear insertion of reactivity, considering an external constant source or with both varying linearly. (author)

  10. Fast, microprocessor driven, data acquisition for Fermilab Experiment E-705

    International Nuclear Information System (INIS)

    Conetti, S.; Haire, M.; Kuchela, K.

    1985-01-01

    Data rate in excess of 10 5 16-bit CAMAC words/sec, with peak rates of up to 2X10 6 words/sec, are expected from Fermilab experiment E-705. To handle such rate, a fast Data Acquisition System was designed, composed of several CAMAC Smart Controllers, sending their data, in a combined serial/parallel organization, to a VME based data collection and forwarding system. Such a system, contained in a VME Crate, consists of homebuilt data receiver and transmitter boards, a Motorola VME-110, 68000 based, Single Board Computer acting as a supervisor, and a large (greater than or equal to4 Mbytes) buffer memory. Data filtering capabilities will be added to the system with the inclusion of several MK 75602 Single Board Computers, acting as processing cells

  11. Characteristics of membrane fouling in submerged membrane bioreactor under sub-critical flux operation.

    Science.gov (United States)

    Su, Y C; Huang, C P; Pan, Jill R; Lee, H C

    2008-01-01

    Recently, the membrane bioreactor (MBR) process has become one of the novel technologies to enhance the performance of biological treatment of wastewater. Membrane bioreactor process uses the membrane unit to replace a sediment tank, and this can greatly enhance treatment performance. However, membrane fouling in MBR restricts its widespread application because it leads to permeate flux decline, making more frequent membrane cleaning and replacement necessary, which then increases operating and maintenance costs. This study investigated the sludge characteristics in membrane fouling under sub-critical flux operation and also assessed the effect of shear stress on membrane fouling. Membrane fouling was slow under sub-critical flux operation. However, as filamentous microbes became dominant in the reactor, membrane fouling increased dramatically due to the increased viscosity and polysaccharides. A close link was found between membrane fouling and the amount of polysaccharides in soluble EPS. The predominant resistance was the cake resistance which could be minimized by increasing the shear stress. However, the resistance of colloids and solutes was not apparently reduced by increasing shear stress. Therefore, smaller particles such as macromolecules (e.g. polysaccharides) may play an important role in membrane fouling under sub-critical flux operation.

  12. Cylindrical target Li-beam-driven hohlraum experiments

    International Nuclear Information System (INIS)

    Derzon, M.S.; Aubert, J.; Chandler, G.A.

    1998-06-01

    The authors performed a series of experiments on the Particle Beam Fusion Accelerator II (PBFA II) in May, 1994, and obtained a brightness temperature of 61 ± 2 eV for an ion-beam heated hohlraum. The hohlraum was a 4-mm-diameter, right-circular cylinder with a 1.5-mm-thick gold wall, a low-density CH foam fill, and a 1.5- or 3-mm-diameter diagnostic aperture in the top. The nominal parameters of the radially-incident PBFA II Li ion beam were 9 MeV peak energy (∼10 MeV at the gas cell) at the target at a peak power of 2.5 ± 0.3 TW/cm 2 and a 15 ns pulse width. Azimuthal variations in intensity of a factor of 3, with respect to the mean, were observed. Nonuniformities in thermal x-ray emission across the area of the diagnostic hole were also observed. Time-dependent hole-closure velocities were measured: the time-averaged velocity of ∼2 cm/micros is in good agreement with sound speed estimates. Unfolded x-ray spectra and brightness temperatures as a function of time are reported and compared to simulations. Hole closure corrections are discussed with comparisons between XRD and bolometer measurements. Temperature scaling with power on target is also presented

  13. A Proton-Driven Plasma Wakefield Acceleration experiment at CERN

    CERN Multimedia

    The AWAKE Collaboration has been formed in order to demonstrate protondriven plasma wakefield acceleration for the first time. This technology could lead to future colliders of high energy but of a much reduced length compared to proposed linear accelerators. The SPS proton beam in the CNGS facility will be injected into a 10m plasma cell where the long proton bunches will be modulated into significantly shorter micro-bunches. These micro-bunches will then initiate a strong wakefield in the plasma with peak fields above 1 GV/m that will be harnessed to accelerate a bunch of electrons from about 20MeV to the GeV scale within a few meters. The experimental program is based on detailed numerical simulations of beam and plasma interactions. The main accelerator components, the experimental area and infrastructure required as well as the plasma cell and the diagnostic equipment are discussed in detail. First protons to the experiment are expected at the end of 2016 and this will be followed by an initial 3–4 yea...

  14. Laser driven shock wave experiments for equation of state studies at megabar pressures

    CERN Document Server

    Pant, H C; Senecha, V K; Bandyopadhyay, S; Rai, V N; Khare, P; Bhat, R K; Gupta, N K; Godwal, B K

    2002-01-01

    We present the results from laser driven shock wave experiments for equation of state (EOS) studies of gold metal. An Nd:YAG laser chain (2 J, 1.06 mu m wavelength, 200 ps pulse FWHM) is used to generate shocks in planar Al foils and Al + Au layered targets. The EOS of gold in the pressure range of 9-13 Mbar is obtained using the impedance matching technique. The numerical simulations performed using the one-dimensional radiation hydrodynamic code support the experimental results. The present experimental data show remarkable agreement with the existing standard EOS models and with other experimental data obtained independently using laser driven shock wave experiments.

  15. Laser-driven proton beams applied to radiobiological experiments

    International Nuclear Information System (INIS)

    Yogo, Akifumi

    2012-01-01

    The proton accelerators based on the high intensity laser system generate shorter and higher pulse beams compared to the conventional particle accelerators used for the cancer therapy. To demonstrate the radiobiological effects of the new proton beams, the program to develop a biological irradiation instrument for the DNA double-strand break was started in the fiscal year 2008. A prototype instrument was made by making use of the J-KAREN (JAEA Kansai Advanced Relativistic Engineering) laser beam. Polyimide thin film targets were used to irradiate A-549 cells. The DNA double-strand break was tested by the fluorescence spectrometry. In the second year the quantitative yield of the DNA double-strand break and its proton dose dependence were measured. The results indicated that they were comparative to the cases of the conventional particle accelerators. In the fiscal year of 2010 the design of the magnetic field for the energy selection has been changed. The new irradiation instrument, the main part of which is only about 40 cm in length as illustrated in the figure, has been constructed and tested. The experiment has been carried out using the human cancer cells (HSG) and the relative biological effectiveness (RBE) has been quantitatively evaluated by the colony assay for varied distribution of the proton beam energy. The survival fractions plotted against the dose were in good agreement with the case of 3 He beam. RBE was found not to be changed up to 1x10 7 Gy/s. Stability of the energy peak, half width and the proton density has been confirmed for this very compact instrument. (S. Funahashi)

  16. Advanced electrical current measurements of microdischarges: evidence of sub-critical pulses and ion currents in barrier discharge in air

    Science.gov (United States)

    Synek, Petr; Zemánek, Miroslav; Kudrle, Vít; Hoder, Tomáš

    2018-04-01

    Electrical current measurements in corona or barrier microdischarges are a challenge as they require both high temporal resolution and a large dynamic range of the current probe used. In this article, we apply a simple self-assembled current probe and compare it to commercial ones. An analysis in the time and frequency domain is carried out. Moreover, an improved methodology is presented, enabling both temporal resolution in sub-nanosecond times and current sensitivity in the order of tens of micro-amperes. Combining this methodology with a high-tech oscilloscope and self-developed software, a unique statistical analysis of currents in volume barrier discharge driven in atmospheric-pressure air is made for over 80 consecutive periods of a 15 kHz applied voltage. We reveal the presence of repetitive sub-critical current pulses and conclude that these can be identified with the discharging of surface charge microdomains. Moreover, extremely low, long-lasting microsecond currents were detected which are caused by ion flow, and are analysed in detail. The statistical behaviour presented gives deeper insight into the discharge physics of these usually undetectable current signals.

  17. Design-theoretical study of cascade CO2 sub-critical mechanical compression/butane ejector cooling cycle

    KAUST Repository

    Petrenko, V.O.

    2011-11-01

    In this paper an innovative micro-trigeneration system composed of a cogeneration system and a cascade refrigeration cycle is proposed. The cogeneration system is a combined heat and power system for electricity generation and heat production. The cascade refrigeration cycle is the combination of a CO2 mechanical compression refrigerating machine (MCRM), powered by generated electricity, and an ejector cooling machine (ECM), driven by waste heat and using refrigerant R600. Effect of the cycle operating conditions on ejector and ejector cycle performances is studied. Optimal geometry of the ejector and performance characteristics of ECM are determined at wide range of the operating conditions. The paper also describes a theoretical analysis of the CO2 sub-critical cycle and shows the effect of the MCRM evaporating temperature on the cascade system performance. The obtained data provide necessary information to design a small-scale cascade system with cooling capacity of 10 kW for application in micro-trigeneration systems. © 2010 Elsevier Ltd and IIR. All rights reserved.

  18. Accelerator driven radiation clean nuclear power system conceptual research symposium

    International Nuclear Information System (INIS)

    Zhao Zhixiang

    2000-06-01

    The R and D of ADS (Accelerators Driven Subcritical System) in China introduced. 31 theses are presented. It includes the basic principle of ADS, accelerators, sub-critical reactors, neutron physics, nuclear data, partitioning and transmutation

  19. A demonstration experiment of steam-driven, high-pressure melt ejection

    International Nuclear Information System (INIS)

    Allen, M.D.; Pitch, M.; Nichols, R.T.

    1990-08-01

    A steam blowdown test was performed at the Surtsey Direct Heating Test Facility to test the steam supply system and burst diaphragm arrangement that will be used in subsequent Surtsey Direct Containment Heating (DCH) experiments. Following successful completion of the steam blowdown test, the HIPS-10S (High-Pressure Melt Streaming) experiment was conducted to demonstrate that the technology to perform steam-driven, high-pressure melt ejection (HPME) experiments has been successfully developed. In addition, the HIPS-10S experiment was used to assess techniques and instrumentation design to create the proper timing of events in HPME experiments. This document discusses the results of this test

  20. Optimization by simulation of the coupling between a sub-critical reactor and its spallation source. Towards a pilot reactor

    International Nuclear Information System (INIS)

    Kerdraon, D.

    2001-10-01

    Accelerator Driven Systems (ADS), based on a proton accelerator and a sub-critical core coupled with a spallation target, offer advantages in order to reduce the nuclear waste radiotoxicity before repository closure. Many studies carried out on the ADS should lead to the definition of an experimental plan which would federate the different works in progress. This thesis deals with the neutronic Monte Carlo simulations with the MCNPX code to optimize such a system in view of a pilot reactor building. First, we have recalled the main neutronic properties of an hybrid reactor. The concept of gas-cooled eXperimental Accelerator Driven System (XADS) chosen for our investigations comes from the preliminary studies done by the Framatome company. In order to transmute minor actinides, we have considered the time evolution of the main fuels which could be reasonably used for the demonstration phases. The neutronic parameters of the reactor, concerning minor actinide transmutation, are reported. Also, we have calculated the characteristic times and the transmutation rates in the case of 99 Tc and 129 I isotopes. We have identified some neutronic differences between an experimental and a power ADS according to the infinite multiplication coefficient, the shape factor and the level of flux to extend the demonstrator concept. We have proposed geometric solutions to keep the radial shape factor of a power ADS acceptable. In the last part, beyond the experimental XADS scope, we have examined the possible transition towards an uranium/thorium cycle based on Molten Salt Reactors using a power ADS in order to generate the required 233 U proportion. (author)

  1. Laser driven inertial fusion: the physical basis of current and recently proposed ignition experiments

    International Nuclear Information System (INIS)

    Atzeni, S

    2009-01-01

    A brief overview of the inertial fusion principles and schemes is presented. The bases for the laser driven ignition experiments programmed for the near future at the National Ignition Facility are outlined. These experiments adopt indirect-drive and aim at central ignition. The principles of alternate approaches, based on direct-drive and different routes to ignition (fast ignition and shock ignition) are also discussed. Gain curves are compared and discussed.

  2. Experimental investigation on flow patterns of RP-3 kerosene under sub-critical and supercritical pressures

    Science.gov (United States)

    Wang, Ning; Zhou, Jin; Pan, Yu; Wang, Hui

    2014-02-01

    Active cooling with endothermic hydrocarbon fuel is proved to be one of the most promising approaches to solve the thermal problem for hypersonic aircraft such as scramjet. The flow patterns of two-phase flow inside the cooling channels have a great influence on the heat transfer characteristics. In this study, phase transition processes of RP-3 kerosene flowing inside a square quartz-glass tube were experimentally investigated. Three distinct phase transition phenomena (liquid-gas two phase flow under sub-critical pressures, critical opalescence under critical pressure, and corrugation under supercritical pressures) were identified. The conventional flow patterns of liquid-gas two phase flow, namely bubble flow, slug flow, churn flow and annular flow are observed under sub-critical pressures. Dense bubble flow and dispersed flow are recognized when pressure is increased towards the critical pressure whilst slug flow, churn flow and annular flow disappear. Under critical pressure, the opalescence phenomenon is observed. Under supercritical pressures, no conventional phase transition characteristics, such as bubbles are observed. But some kind of corrugation appears when RP-3 transfers from liquid to supercritical. The refraction index variation caused by sharp density gradient near the critical temperature is thought to be responsible for this corrugation.

  3. Laser driven shock wave experiments for equation of state studies at megabar pressures

    International Nuclear Information System (INIS)

    Pant, H C; Shukla, M; Senecha, V K; Bandyopadhyay, S; Rai, V N; Khare, P; Bhat, R K; Gupta, N K; Godwal, B K

    2002-01-01

    We present the results from laser driven shock wave experiments for equation of state (EOS) studies of gold metal. An Nd:YAG laser chain (2 J, 1.06 μm wavelength, 200 ps pulse FWHM) is used to generate shocks in planar Al foils and Al + Au layered targets. The EOS of gold in the pressure range of 9-13 Mbar is obtained using the impedance matching technique. The numerical simulations performed using the one-dimensional radiation hydrodynamic code support the experimental results. The present experimental data show remarkable agreement with the existing standard EOS models and with other experimental data obtained independently using laser driven shock wave experiments

  4. Nuclear models, experiments and data libraries needed for numerical simulation of accelerator-driven system

    International Nuclear Information System (INIS)

    Bauge, E.; Bersillon, O.

    2000-01-01

    This paper presents the transparencies of the speech concerning the nuclear models, experiments and data libraries needed for numerical simulation of Accelerator-Driven Systems. The first part concerning the nuclear models defines the spallation process, the corresponding models (intra-nuclear cascade, statistical model, Fermi breakup, fission, transport, decay and macroscopic aspects) and the code systems. The second part devoted to the experiments presents the angular measurements, the integral measurements, the residual nuclei and the energy deposition. In the last part, dealing with the data libraries, the author details the fundamental quantities as the reaction cross-section, the low energy transport databases and the decay libraries. (A.L.B.)

  5. Conceptual design based on scale laws and algorithms for sub-critical transmutation reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Gu; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    In order to conduct the effective integration of computer-aided conceptual design for integrated nuclear power reactor, not only is a smooth information flow required, but also decision making for both conceptual design and construction process design must be synthesized. In addition to the aboves, the relations between the one step and another step and the methodologies to optimize the decision variables are verified, in this paper especially, that is, scaling laws and scaling criteria. In the respect with the running of the system, the integrated optimization process is proposed in which decisions concerning both conceptual design are simultaneously made. According to the proposed reactor types and power levels, an integrated optimization problems are formulated. This optimization is expressed as a multi-objective optimization problem. The algorithm for solving the problem is also presented. The proposed method is applied to designing a integrated sub-critical reactors. 6 refs., 5 figs., 1 tab. (Author)

  6. Present status of Monte Carlo seminar for sub-criticality safety analysis in Japan

    International Nuclear Information System (INIS)

    Sakurai, Kiyoshi

    2003-01-01

    This paper provides overview of the methods and results of a series of sub-criticality safety analysis seminars for nuclear fuel cycle facility with the Monte Carlo method held in Japan from July 2000 to July 2003. In these seminars, MCNP-4C2 system (MS-DOS version) was installed in note-type personal computers for participants. Fundamental theory of reactor physics and Monte Carlo simulation as well as the contents of the MCNP manual were lectured. Effective neutron multiplication factors and neutron spectra were calculated for some examples such as JCO deposit tank, JNC uranium solution storage tank, JNC plutonium solution storage tank and JAERI TCA core. Management for safety of nuclear fuel cycle facilities was discussed in order to prevent criticality accidents in some of the seminars. (author)

  7. Conceptual design based on scale laws and algorithms for sub-critical transmutation reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kwang Gu; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    In order to conduct the effective integration of computer-aided conceptual design for integrated nuclear power reactor, not only is a smooth information flow required, but also decision making for both conceptual design and construction process design must be synthesized. In addition to the aboves, the relations between the one step and another step and the methodologies to optimize the decision variables are verified, in this paper especially, that is, scaling laws and scaling criteria. In the respect with the running of the system, the integrated optimization process is proposed in which decisions concerning both conceptual design are simultaneously made. According to the proposed reactor types and power levels, an integrated optimization problems are formulated. This optimization is expressed as a multi-objective optimization problem. The algorithm for solving the problem is also presented. The proposed method is applied to designing a integrated sub-critical reactors. 6 refs., 5 figs., 1 tab. (Author)

  8. A unified modeling approach for physical experiment design and optimization in laser driven inertial confinement fusion

    Energy Technology Data Exchange (ETDEWEB)

    Li, Haiyan [Mechatronics Engineering School of Guangdong University of Technology, Guangzhou 510006 (China); Huang, Yunbao, E-mail: Huangyblhy@gmail.com [Mechatronics Engineering School of Guangdong University of Technology, Guangzhou 510006 (China); Jiang, Shaoen, E-mail: Jiangshn@vip.sina.com [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China); Jing, Longfei, E-mail: scmyking_2008@163.com [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China); Tianxuan, Huang; Ding, Yongkun [Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang 621900 (China)

    2015-11-15

    Highlights: • A unified modeling approach for physical experiment design is presented. • Any laser facility can be flexibly defined and included with two scripts. • Complex targets and laser beams can be parametrically modeled for optimization. • Automatically mapping of laser beam energy facilitates targets shape optimization. - Abstract: Physical experiment design and optimization is very essential for laser driven inertial confinement fusion due to the high cost of each shot. However, only limited experiments with simple structure or shape on several laser facilities can be designed and evaluated in available codes, and targets are usually defined by programming, which may lead to it difficult for complex shape target design and optimization on arbitrary laser facilities. A unified modeling approach for physical experiment design and optimization on any laser facilities is presented in this paper. Its core idea includes: (1) any laser facility can be flexibly defined and included with two scripts, (2) complex shape targets and laser beams can be parametrically modeled based on features, (3) an automatically mapping scheme of laser beam energy onto discrete mesh elements of targets enable targets or laser beams be optimized without any additional interactive modeling or programming, and (4) significant computation algorithms are additionally presented to efficiently evaluate radiation symmetry on the target. Finally, examples are demonstrated to validate the significance of such unified modeling approach for physical experiments design and optimization in laser driven inertial confinement fusion.

  9. KNMI DataLab experiences in serving data-driven innovations

    Science.gov (United States)

    Noteboom, Jan Willem; Sluiter, Raymond

    2016-04-01

    Climate change research and innovations in weather forecasting rely more and more on (Big) data. Besides increasing data from traditional sources (such as observation networks, radars and satellites), the use of open data, crowd sourced data and the Internet of Things (IoT) is emerging. To deploy these sources of data optimally in our services and products, KNMI has established a DataLab to serve data-driven innovations in collaboration with public and private sector partners. Big data management, data integration, data analytics including machine learning and data visualization techniques are playing an important role in the DataLab. Cross-domain data-driven innovations that arise from public-private collaborative projects and research programmes can be explored, experimented and/or piloted by the KNMI DataLab. Furthermore, advice can be requested on (Big) data techniques and data sources. In support of collaborative (Big) data science activities, scalable environments are offered with facilities for data integration, data analysis and visualization. In addition, Data Science expertise is provided directly or from a pool of internal and external experts. At the EGU conference, gained experiences and best practices are presented in operating the KNMI DataLab to serve data-driven innovations for weather and climate applications optimally.

  10. Experiments on vibration-driven stick-slip locomotion: A sliding bifurcation perspective

    Science.gov (United States)

    Du, Zhouwei; Fang, Hongbin; Zhan, Xiong; Xu, Jian

    2018-05-01

    Dry friction appears at the contact interface between two surfaces and is the source of stick-slip vibrations. Instead of being a negative factor, dry friction is essential for vibration-driven locomotion system to take effect. However, the dry-friction-induced stick-slip locomotion has not been fully understood in previous research, especially in terms of experiments. In this paper, we experimentally study the stick-slip dynamics of a vibration-driven locomotion system from a sliding bifurcation perspective. To this end, we first design and build a vibration-driven locomotion prototype based on an internal piezoelectric cantilever. By utilizing the mechanical resonance, the small piezoelectric deformation is significantly amplified to drive the prototype to achieve effective locomotion. Through identifying the stick-slip characteristics in velocity histories, we could categorize the system's locomotion into four types and obtain a stick-slip categorization diagram. In each zone of the diagram the locomotion exhibits qualitatively different stick-slip dynamics. Such categorization diagram is actually a sliding bifurcation diagram; crossing from one stick-slip zone to another corresponds to the triggering of a sliding bifurcation. In addition, a simplified single degree-of-freedom model is established, with the rationality of simplification been explained theoretically and numerically. Based on the equivalent model, a numerical stick-slip categorization is also obtained, which shows good agreement with the experiments both qualitatively and quantitatively. To the best of our knowledge, this is the first work that experimentally generates a sliding bifurcation diagram. The obtained stick-slip categorizations deepen our understanding of stick-slip dynamics in vibration-driven systems and could serve as a base for system design and optimization.

  11. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    International Nuclear Information System (INIS)

    Wender, S.A.; Venneri, F.; Bowman, C.D.; Arthur, E.D.; Heighway, E.A.; Beard, C.A.; Bracht, R.R.; Buksa, J.J.; Chavez, W.; DeVolder, B.G.

    1994-01-01

    A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning or transmutation of commercial spent fuel or energy production from thorium. The experiment will be operated at power levels up to 5 MW t

  12. Double-slit experiment with single wave-driven particles and its relation to quantum mechanics

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Madsen, Jacob; Reichelt, Christian Günther

    2015-01-01

    even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes...... place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our...... results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schro...

  13. Understanding hospital meal experiences by means of participant-driven-photo-elicitation.

    Science.gov (United States)

    Justesen, Lise; Mikkelsen, Bent E; Gyimóthy, Szilvia

    2014-04-01

    A patients' hospital meal experiences can be complex and often difficult to capture using traditional methods. This study investigated patients' hospital meal experiences using participant-driven-photo-elicitation (PDPE). PDPE invites respondents to photograph their daily lives and combines this with interviews, which can provide deeper insight into multisensory experiences beyond verbal or written discourse. The sample consisted of eight hospitalised patients. Patients completed a photo-essay of their hospital meal experience during a single day at a Danish hospital and afterwards participated in an open-ended interview. Two inductive analytical approaches were selected to assess the patients' reflections on their hospital meal experiences. First, the interview transcripts were analysed using the Semiotic Analysis approach using qualitative data analysis software NVivo 9. Second, the 91 produced photographs and the participants' engagement with the photographs were analysed by means of a Reflexive Content Analysis. The study found that PDPE is a research method that can be used for expanding the conceptualisation of hospital meal experiences, revealing the significance of the meal context, materiality and memories beyond food per se. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Design of an accelerator-driven system for the destruction of nuclear waste

    International Nuclear Information System (INIS)

    Kadi, Y.; Revol, J.P.

    2003-01-01

    Progress in particle accelerator technology makes it possible to use a proton accelerator to produce energy and to destroy nuclear waste efficiently. The Energy Amplifier (EA) proposed by Carlo Rubbia and his group is a sub-critical fast neutron system driven by a proton accelerator. It is particularly attractive for destroying, through fission, transuranic elements produced by present nuclear reactors. The EA could also transform efficiently and at minimal cost long-lived fission fragments using the concept of Adiabatic Resonance Crossing (ARC) recently tested at CERN with the TARC experiment. (author)

  15. BOW SHOCK FRAGMENTATION DRIVEN BY A THERMAL INSTABILITY IN LABORATORY ASTROPHYSICS EXPERIMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki-Vidal, F.; Lebedev, S. V.; Pickworth, L. A.; Swadling, G. F.; Skidmore, J.; Hall, G. N.; Bennett, M.; Bland, S. N.; Burdiak, G.; De Grouchy, P.; Music, J.; Suttle, L. [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BW (United Kingdom); Ciardi, A. [Sorbonne Universités, UPMC Univ. Paris 6, UMR 8112, LERMA, F-75005, Paris (France); Rodriguez, R.; Gil, J. M.; Espinosa, G. [Departamento de Fisica de la Universidad de Las Palmas de Gran Canaria, E-35017 Las Palmas de Gran Canaria (Spain); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Hansen, E.; Frank, A., E-mail: f.suzuki@imperial.ac.uk [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States)

    2015-12-20

    The role of radiative cooling during the evolution of a bow shock was studied in laboratory-astrophysics experiments that are scalable to bow shocks present in jets from young stellar objects. The laboratory bow shock is formed during the collision of two counterstreaming, supersonic plasma jets produced by an opposing pair of radial foil Z-pinches driven by the current pulse from the MAGPIE pulsed-power generator. The jets have different flow velocities in the laboratory frame, and the experiments are driven over many times the characteristic cooling timescale. The initially smooth bow shock rapidly develops small-scale nonuniformities over temporal and spatial scales that are consistent with a thermal instability triggered by strong radiative cooling in the shock. The growth of these perturbations eventually results in a global fragmentation of the bow shock front. The formation of a thermal instability is supported by analysis of the plasma cooling function calculated for the experimental conditions with the radiative packages ABAKO/RAPCAL.

  16. Sub-critical cohesive crack propagation with hydro-mechanical coupling and friction

    Directory of Open Access Journals (Sweden)

    S. Valente

    2016-01-01

    Full Text Available Looking at the long-time behaviour of a dam, it is necessary to assume that the water can penetrate a possible crack washing away some components of the concrete. This type of corrosion reduces the tensile strength and fracture energy of the concrete compared to the same parameters measured during a short-time laboratory test. This phenomenon causes the so called sub-critical crack propagation. That is the reason why the International Commission of Large Dams recommends to neglect the tensile strength of the joint between the dam and the foundation, which is the weakest point of a gravity dam. In these conditions a shear displacement discontinuity starts growing in a point, called Fictitious Crack Tip (shortened FCT, which is still subjected to a compression stress. In order to manage this problem, in this paper the cohesive crack model is re-formulated with the focus on the shear stress component. In this context, the classical Newton-Raphson method fails to converge to an equilibrium state. Therefore the approach used is based on two stages: (a a global one in which the FCT is moved ahead of one increment; (b a local one in which the non-linear conditions occurring in the Fracture Process Zone are taken into account. This two-stage approach, which is known in the literature as a Large Time Increment method, is able to model three different mechanical regimes occurring during the crack propagation between a dam and the foundation rock.

  17. Recycling high-performance carbon fiber reinforced polymer composites using sub-critical and supercritical water

    Science.gov (United States)

    Knight, Chase C.

    Carbon fiber reinforced plastics (CFRP) are composite materials that consist of carbon fibers embedded in a polymer matrix, a combination that yields materials with properties exceeding the individual properties of each component. CFRP have several advantages over metals: they offer superior strength to weight ratios and superior resistance to corrosion and chemical attack. These advantages, along with continuing improvement in manufacturing processes, have resulted in rapid growth in the number of CFRP products and applications especially in the aerospace/aviation, wind energy, automotive, and sporting goods industries. Due to theses well-documented benefits and advancements in manufacturing capabilities, CFRP will continue to replace traditional materials of construction throughout several industries. However, some of the same properties that make CFRP outstanding materials also pose a major problem once these materials reach the end of service life. They become difficult to recycle. With composite consumption in North America growing by almost 5 times the rate of the US GDP in 2012, this lack of recyclability is a growing concern. As consumption increases, more waste will inevitably be generated. Current composite recycling technologies include mechanical recycling, thermal processing, and chemical processing. The major challenge of CFRP recycling is the ability to recover materials of high-value and preserve their properties. To this end, the most suitable technology is chemical processing, where the polymer matrix can be broken down and removed from the fiber, with limited damage to the fibers. This can be achieved using high concentration acids, but such a process is undesirable due to the toxicity of such materials. A viable alternative to acid is water in the sub-critical and supercritical region. Under these conditions, the behavior of this abundant and most environmentally friendly solvent resembles that of an organic compound, facilitating the breakdown

  18. Sub-critical crack growth and clad integrity in a PWR reactor pressure vessel

    International Nuclear Information System (INIS)

    Tice, D.R.; Foreman, A.J.E.; Sharples, J.K.

    1987-10-01

    The possibility of in-service growth of sub-critical defects in a PWR reactor pressure vessel to a critical size which could result in vessel failure was addressed in both the 1976 and 1982 reports of the Light Water Reactor Study Group (LWRSG), under the Chairmanship of Dr W Marshall (now Lord Marshall). An addendum to this report was published by UKAEA in April 1987. The section of the addendum dealing with subcritical crack growth and the related issue of integrity of the stainless steel cladding on the inner vessel surface is reproduced in this report. This section of the LWRSG addendum provides a review of the current status of fatigue crack growth and environmentally assisted cracking research for pressure vessel steels in light water reactor environments, as well as a review of developments in crack growth assessment methods. The review concludes that the alternative assessment procedures now being developed give a more realistic prediction of in service crack growth than the ASME Section XI Appendix A fatigue crack growth curves. (author)

  19. Study on the method of determining the sub-criticality of a reactor via the measurement of core neutron flux spatial distribution

    International Nuclear Information System (INIS)

    Ma Aifeng; Jiang Xiaofeng; Zhang Shaohong

    2007-01-01

    A new methodology based on rigorous reactor physics theory astead of the point reactor assumption was proposed to determine or monitor the sub-criticality ora reactor, especially the sub-critical reactor of ADS, via the measurement of in-core flux spatial distribution. Preliminary numerical studies on the 1st ADS sub-critical experimental facilities-Venus No.1 in China have demonstrated the feasibility of this new method. Related discussions pointed out the potential applications of the method. (authors)

  20. The Texts of the Instruments connected with the Agency's Assistance to Finland in Establishing a Sub-Critical Assemblies Project

    International Nuclear Information System (INIS)

    1964-01-01

    The text of the Project Agreement between the Agency and the Government of Finland in connection with the Agency's assistance to that Government in establishing a sub-critical assemblies project is reproduced in Part I of this document for the information of all Members. This Agreement entered into force on 30 July 1963

  1. The Texts of the Instruments connected with the Agency's Assistance to Finland in Establishing a Sub-Critical Assemblies Project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1964-02-10

    The text of the Project Agreement between the Agency and the Government of Finland in connection with the Agency's assistance to that Government in establishing a sub-critical assemblies project is reproduced in Part I of this document for the information of all Members. This Agreement entered into force on 30 July 1963.

  2. Data Driven Trigger Design and Analysis for the NOvA Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Kurbanov, Serdar [Univ. of Virginia, Charlottesville, VA (United States)

    2016-01-01

    This thesis primarily describes analysis related to studying the Moon shadow with cosmic rays, an analysis using upward-going muons trigger data, and other work done as part of MSc thesis work conducted at Fermi National Laboratory. While at Fermilab I made hardware and software contributions to two experiments - NOvA and Mu2e. NOvA is a neutrino experiment with the primary goal of measuring parameters related to neutrino oscillation. This is a running experiment, so it's possible to provide analysis of real beam and cosmic data. Most of this work was related to the Data-Driven Trigger (DDT) system of NOvA. The results of the Upward-Going muon analysis was presented at ICHEP in August 2016. The analysis demonstrates the proof of principle for a low-mass dark matter search. Mu2e is an experiment currently being built at Fermilab. Its primary goal is to detect the hypothetical neutrinoless conversion from a muon into an electron. I contributed to the production and tests of Cathode Strip Chambers (CSCs) which are required for testing the Cosmic Ray Veto (CRV) system for the experiment. This contribution is described in the last chapter along with a short description of the technical work provided for the DDT system of the NOvA experiment. All of the work described in this thesis will be extended by the next generation of UVA graduate students and postdocs as new data is collected by the experiment. I hope my eorts of have helped lay the foundation for many years of beautiful results from Mu2e and NOvA.

  3. Alpha-Driven MHD and MHD-Induced Alpha Loss in TFTR DT Experiments

    Science.gov (United States)

    Chang, Zuoyang

    1996-11-01

    Theoretical calculation and numerical simulation indicate that there can be interesting interactions between alpha particles and MHD activity which can adversely affect the performance of a tokamak reactor (e.g., ITER). These interactions include alpha-driven MHD, like the toroidicity-induced-Alfven-eigenmode (TAE) and MHD induced alpha particle losses or redistribution. Both phenomena have been observed in recent TFTR DT experiments. Weak alpha-driven TAE activity was observed in a NBI-heated DT experiment characterized by high q0 ( >= 2) and low core magnetic shear. The TAE mode appears at ~30-100 ms after the neutral beam turning off approximately as predicted by theory. The mode has an amplitude measured by magnetic coils at the edge tildeB_p ~1 mG, frequency ~150-190 kHz and toroidal mode number ~2-3. It lasts only ~ 30-70 ms and has been seen only in DT discharges with fusion power level about 1.5-2.0 MW. Numerical calculation using NOVA-K code shows that this type of plasma has a big TAE gap. The calculated TAE frequency and mode number are close to the observation. (2) KBM-induced alpha particle loss^1. In some high-β, high fusion power DT experiments, enhanced alpha particle losses were observed to be correlated to the high frequency MHD modes with f ~100-200 kHz (the TAE frequency would be two-times higher) and n ~5-10. These modes are localized around the peak plasma pressure gradient and have ballooning characteristics. Alpha loss increases by 30-100% during the modes. Particle orbit simulations show the added loss results from wave-particle resonance. Linear instability analysis indicates that the plasma is unstable to the kinetic MHD ballooning modes (KBM) driven primarily by strong local pressure gradients. ----------------- ^1Z. Chang, et al, Phys. Rev. Lett. 76 (1996) 1071. In collaberation with R. Nazikian, G.-Y. Fu, S. Batha, R. Budny, L. Chen, D. Darrow, E. Fredrickson, R. Majeski, D. Mansfield, K. McGuire, G. Rewoldt, G. Taylor, R. White, K

  4. Double-slit experiment with single wave-driven particles and its relation to quantum mechanics.

    Science.gov (United States)

    Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T; Bohr, Tomas

    2015-07-01

    In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

  5. Double-slit experiment with single wave-driven particles and its relation to quantum mechanics

    Science.gov (United States)

    Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T.; Bohr, Tomas

    2015-07-01

    In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006), 10.1103/PhysRevLett.97.154101] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.

  6. Modeling and simulations of radiative blast wave driven Rayleigh-Taylor instability experiments

    Science.gov (United States)

    Shimony, Assaf; Huntington, Channing M.; Trantham, Matthew; Malamud, Guy; Elbaz, Yonatan; Kuranz, Carolyn C.; Drake, R. Paul; Shvarts, Dov

    2017-10-01

    Recent experiments at the National Ignition Facility measured the growth of Rayleigh-Taylor RT instabilities driven by radiative blast waves, relevant to astrophysics and other HEDP systems. We constructed a new Buoyancy-Drag (BD) model, which accounts for the ablation effect on both bubble and spike. This ablation effect is accounted for by using the potential flow model ]Oron et al PoP 1998], adding another term to the classical BD formalism: βDuA / u , where β the Takabe constant, D the drag term, uA the ablation velocity and uthe instability growth velocity. The model results are compared with the results of experiments and 2D simulations using the CRASH code, with nominal radiation or reduced foam opacity (by a factor of 1000). The ablation constant of the model, βb / s, for the bubble and for the spike fronts, are calibrated using the results of the radiative shock experiments. This work is funded by the Lawrence Livermore National Laboratory under subcontract B614207, and was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

  7. Implications of recent implantation-driven permeation experiments for fusion reactor safety

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Anderl, R.A.; Struttmann, D.A.

    1986-01-01

    Metal structures exposed to the plasma in tritium-burning fusion reactors will be subject to implantation-driven permeation (IDP) of tritium. Permeation rates for IDP in fusion structural materials are usually high because the tritium atoms enter the material without having to go through the dissociation and solution steps required of tritium-bearing gas molecules. These surface processes, which may be rate limiting in PDP, actually enhance permeation in IDP by inhibiting the return of tritium to the plasma side of the structure. Experiments have been conducted at the Idaho National Engineering Laboratory (INEL) to investigate the nature of IDP by simulating conditions experienced by structures exposed to the plasma. These experiments have shown that surface conditions are important to tritium permeation in materials endothermic to hydrogen solution such as austenitic and ferritic steels. In reactive metals such as vanadium, surface processes appear to totally control the permeation. The purpose of this paper is to review the progress of those experiments and to discuss the implications that the results have regarding the tritium-related safety concerns of fusion reactors

  8. Computational modeling of z-pinch-driven hohlraum experiments on Z

    International Nuclear Information System (INIS)

    Vesey, R.A.; Porter, J.L. Jr.; Cuneo, M.E.

    1999-01-01

    The high-yield inertial confinement fusion concept based on a double-ended z-pinch driven hohlraum tolerates the degree of spatial inhomogeneity present in z-pinch plasma radiation sources by utilizing a relatively large hohlraum wall surface to provide spatial smoothing of the radiation delivered to the fusion capsule. The z-pinch radiation sources are separated from the capsule by radial spoke arrays. Key physics issues for this concept are the behavior of the spoke array (effect on the z-pinch performance, x-ray transmission) and the uniformity of the radiation flux incident on the surface of the capsule. Experiments are underway on the Z accelerator at Sandia National laboratories to gain understanding of these issues in a single-sided drive geometry. These experiments seek to measure the radiation coupling among the z-pinch, source hohlraum, and secondary hohlraum, as well as the uniformity of the radiation flux striking a foam witness ball diagnostic positioned in the secondary hohlraum. This paper will present the results of computational modeling of various aspects of these experiments

  9. Ground-based PIV and numerical flow visualization results from the Surface Tension Driven Convection Experiment

    Science.gov (United States)

    Pline, Alexander D.; Werner, Mark P.; Hsieh, Kwang-Chung

    1991-01-01

    The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the United States Microgravity Laboratory-1 (USML-1) Spacelab mission planned for June, 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electric, two dimensional Particle Image Velocimetry (PIV) technique called Particle Displacement Tracking (PDT), which uses a simple space domain particle tracking algorithm. Results using the ground based STDCE hardware, with a radiant flux heating mode, and the PDT system are compared to numerical solutions obtained by solving the axisymmetric Navier Stokes equations with a deformable free surface. The PDT technique is successful in producing a velocity vector field and corresponding stream function from the raw video data which satisfactorily represents the physical flow. A numerical program is used to compute the velocity field and corresponding stream function under identical conditions. Both the PDT system and numerical results were compared to a streak photograph, used as a benchmark, with good correlation.

  10. A vibrating membrane bioreactor operated at supra- and sub-critical flux: Influence of extracellular polymeric substances from yeast cells

    DEFF Research Database (Denmark)

    Beier, Søren Prip; Jonsson, Gunnar Eigil

    2007-01-01

    A vibrating membrane bioreactor, in which the fouling problems are reduced by vibrating a hollow fiber membrane module, has been tested in constant flux microfiltration above (supra-critical) and below (sub-critical) an experimentally determined critical flux. Suspensions of bakers yeast cells were...... chosen as filtration medium (dry weight 4 g/l). The influence of extracellular polymeric substances (EPS) from the yeast cells is evaluated by UV absorbance measurements of the bulk supernatant during filtration. The critical flux seems to be an interval or a relative value rather than an absolute value....... Filtration just below the critical flux (sub-critical) seems to be a good compromise between acceptable flux level and acceptable increase of fouling resistance and trans-membrane pressure (TMP) in a given time period. EPS from the yeast cells causes the membrane module to foul and part of the fouling...

  11. The Texts of the Instruments connected with the Agency's Assistance to Mexico in Establishing a Sub-Critical Assembly Project

    International Nuclear Information System (INIS)

    1966-01-01

    The texts of the Supply Agreement between the Agency and the Governments of Mexico and the United States of America, and of the Project Agreement between the Agency and the Government of Mexico in connection with the Agency's assistance to that Government in establishing a sub-critical assembly project.. are reproduced in this document for the information of all Members. Both Agreements entered into force on 20 June 1966

  12. The Texts of the Instruments connected with the Agency's Assistance to Mexico in Establishing a Sub-Critical Assembly Project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-10-25

    The texts of the Supply Agreement between the Agency and the Governments of Mexico and the United States of America, and of the Project Agreement between the Agency and the Government of Mexico, connected with the Agency's assistance to the latter Government in establishing a sub-critical assembly project, are reproduced in this document for the information of all Members. Both Agreements entered into force on 23 August 1967.

  13. The Texts of the Instruments connected with the Agency's Assistance to Mexico in Establishing a Sub-Critical Assembly Project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-07-07

    The texts of the Supply Agreement between the Agency and the Governments of Mexico and the United States of America, and of the Project Agreement between the Agency and the Government of Mexico in connection with the Agency's assistance to that Government in establishing a sub-critical assembly project.. are reproduced in this document for the information of all Members. Both Agreements entered into force on 20 June 1966.

  14. The Texts of the Instruments connected with the Agency's Assistance to Mexico in Establishing a Sub-Critical Assembly Project

    International Nuclear Information System (INIS)

    1967-01-01

    The texts of the Supply Agreement between the Agency and the Governments of Mexico and the United States of America, and of the Project Agreement between the Agency and the Government of Mexico, connected with the Agency's assistance to the latter Government in establishing a sub-critical assembly project, are reproduced in this document for the information of all Members. Both Agreements entered into force on 23 August 1967

  15. DESIGN OF LABORATORY EXPERIMENTS TO STUDY PHOTOIONIZATION FRONTS DRIVEN BY THERMAL SOURCES

    International Nuclear Information System (INIS)

    Drake, R. P.; Keiter, P. A.; Davis, J. S.; Patterson, C. R; Hazak, G.; Frank, A.; Blackman, E. G.; Busquet, Michel

    2016-01-01

    This paper analyzes the requirements of a photoionization-front experiment that could be driven in the laboratory, using thermal sources to produce the necessary flux of ionizing photons. It reports several associated conclusions. Such experiments will need to employ the largest available facilities, capable of delivering many kJ to MJ of energy to an X-ray source. They will use this source to irradiate a volume of neutral gas, likely of N, on a scale of a few mm to a few cm, increasing with source energy. For a gas pressure of several to ten atmospheres at room temperature, and a source temperature near 100 eV, one will be able to drive a photoionization front through a system of tens to hundreds of photon mean free paths. The front should make the familiar transition from the so-called R-Type to D-Type as the radiation flux diminishes with distance. The N is likely to reach the He-like state. Preheating from the energetic photons appears unlikely to become large enough to alter the essential dynamics of the front beyond some layer near the surface. For well-chosen experimental conditions, competing energy transport mechanisms are small.

  16. DESIGN OF LABORATORY EXPERIMENTS TO STUDY PHOTOIONIZATION FRONTS DRIVEN BY THERMAL SOURCES

    Energy Technology Data Exchange (ETDEWEB)

    Drake, R. P.; Keiter, P. A.; Davis, J. S.; Patterson, C. R [Climate and Space Science, University of Michigan, Ann Arbor, MI 48109 (United States); Hazak, G. [Physics Department, Nuclear Research Center-Negev (Israel); Frank, A.; Blackman, E. G. [Physics and Astronomy, University of Rochester, Rochester, NY 14611 (United States); Busquet, Michel, E-mail: rpdrake@umich.edu [ARTEP Incorporated, Ellicot City, MD 21042 (United States)

    2016-12-20

    This paper analyzes the requirements of a photoionization-front experiment that could be driven in the laboratory, using thermal sources to produce the necessary flux of ionizing photons. It reports several associated conclusions. Such experiments will need to employ the largest available facilities, capable of delivering many kJ to MJ of energy to an X-ray source. They will use this source to irradiate a volume of neutral gas, likely of N, on a scale of a few mm to a few cm, increasing with source energy. For a gas pressure of several to ten atmospheres at room temperature, and a source temperature near 100 eV, one will be able to drive a photoionization front through a system of tens to hundreds of photon mean free paths. The front should make the familiar transition from the so-called R-Type to D-Type as the radiation flux diminishes with distance. The N is likely to reach the He-like state. Preheating from the energetic photons appears unlikely to become large enough to alter the essential dynamics of the front beyond some layer near the surface. For well-chosen experimental conditions, competing energy transport mechanisms are small.

  17. Power reactors and sub-critical blanket systems with lead and lead-bismuth as coolant and/or target material. Utilization and transmutation of actinides and long lived fission products

    International Nuclear Information System (INIS)

    2003-05-01

    High level radioactive waste disposal is an issue of great importance in the discussion of the sustainability of nuclear power generation. The main contributors to the high radioactivity are the fission products and the minor actinides. The long lived fission products and minor actinides set severe demands on the arrangements for safe waste disposal. Fast reactors and accelerator driven systems (ADS) are under development in Member States to reduce the long term hazard of spent fuel and radioactive waste, taking advantage of their incineration and transmutation capability. Important R and D programmes are being undertaken in many Member States to substantiate this option and advance the basic knowledge in this innovative area of nuclear energy development. The conceptual design of the lead cooled fast reactor concept BREST-OD-300, as well as various other conceptual designs of lead/lead-bismuth cooled fast reactors have been developed to meet enhanced safety and non-proliferation requirements, aiming at both energy production and transmutation of nuclear waste. Some R and D studies indicate that the use of lead and lead-bismuth coolant has some advantages in comparison with existing sodium cooled fast reactor systems, e.g.: simplified design of fast reactor core and BOP, enhanced inherent safety, and easier radwaste management in related fuel cycles. Moreover, various ADS conceptual designs with lead and lead-bismuth as target material and coolant also have been pursued. The results to date are encouraging, indicating that the ADS has the potential to offer an option for meeting the challenges of the back end fuel cycle. During the last decade, there have been substantial advances in several countries with their own R and D programme in the fields of lead/lead-bismuth cooled critical and sub-critical concepts. coolant technology, and experimental validation. In this context, international exchange of information and experience, as well as international

  18. Recovery of Palm Oil and Valuable Material from Oil Palm Empty Fruit Bunch by Sub-critical Water.

    Science.gov (United States)

    Ahmad Kurnin, Nor Azrin; Shah Ismail, Mohd Halim; Yoshida, Hiroyuki; Izhar, Shamsul

    2016-01-01

    Oil palm empty fruit bunch (EFB) is one of the solid wastes produced in huge volume by palm oil mill. Whilst it still contains valuable oil, approximately 22.6 million tons is generated annually and treated as solid waste. In this work, sub-critical water (sub-cw) was used to extract oil, sugar and tar from spikelet of EFB. The spikelet was treated with sub-cw between 180-280°C and a reaction time of 2 and 5 minutes. The highest yield of oil was 0.075 g-oil/g-dry EFB, obtained at 240°C and reaction time of 5 minutes. Astonishingly, oil that was extracted through this method was 84.5% of that obtained through Soxhlet method using hexane. Yield of oil extracted was strongly affected by the reaction temperature and time. Higher reaction temperature induces the dielectric constant of water towards the non-polar properties of solvent; thus increases the oil extraction capability. Meanwhile, the highest yield of sugar was 0.20 g-sugar/g-dry EFB obtained at 220°C. At this temperature, the ion product of water is high enough to enable maximum sub-critical water hydrolysis reaction. This study showed that oil and other valuable material can be recovered using water at sub-critical condition, and most attractive without the use of harmful organic solvent.

  19. AWAKE Design Report: A Proton-Driven Plasma Wakefield Acceleration Experiment at CERN

    CERN Document Server

    Caldwell, A; Lotov, K; Muggli, P; Wing, M

    2013-01-01

    The AWAKE Collaboration has been formed in order to demonstrate proton driven plasma wakefield acceleration for the first time. This technology could lead to future colliders of high energy but of a much reduced length compared to proposed linear accelerators. The SPS proton beam in the CNGS facility will be injected into a 10m plasma cell where the long proton bunches will be modulated into significantly shorter micro-bunches. These micro-bunches will then initiate a strong wakefield in the plasma with peak fields above 1 GV/m that will be harnessed to accelerate a bunch of electrons from about 20MeV to the GeV scale within a few meters. The experimental program is based on detailed numerical simulations of beam and plasma interactions. The main accelerator components, the experimental area and infrastructure required as well as the plasma cell and the diagnostic equipment are discussed in detail. First protons to the experiment are expected at the end of 2015 and this will be followed by an initial 3–4 ye...

  20. Observation of Beam Driven Modes during Neutral Beam Heating on the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; Gorelenkov, E.D.; Cheng, C.Z.; Bell, R.; Darrow, D.; Johnson, D.; Kaye, S.; LeBlanc, B.; Menard, J.; Kubota, S.; Peebles, W.

    2001-01-01

    With the first injection of neutral beams on the National Spherical Torus Experiment (NSTX), a broad and complicated spectrum of coherent modes was seen between approximately 0.4 MHz and 2.5 MHz [where f(subscript ''ci'')] for deuterium is approximately 2.2 MHz. The modes have been observed with high bandwidth magnetic pick-up coils and with a reflectometer. The parametric scaling of the mode frequency with density and magnetic field is consistent with Alfvenic modes (linear in B, inversely with the square root of density). These modes have been identified as magnetosonic waves or compressional Alfven eigenmodes (CAE) excited by a cyclotron resonance with the neutral-beam ions. Modes have also been observed in the frequency range 50-150 kHz with toroidal mode numbers n = 1-5. These lower frequency modes are thought to be related to the TAE [Toroidal Alfven Eigenmode] seen commonly in tokamaks and driven by energetic fast ion populations resulting from ICRF [ion cyclotron range of frequency] and NBI [neutral-beam injection] heating. There is no clear indication of enhanced fast ion losses associated with the modes

  1. Laser-driven Mach waves for gigabar-range shock experiments

    Science.gov (United States)

    Swift, Damian; Lazicki, Amy; Coppari, Federica; Saunders, Alison; Nilsen, Joseph

    2017-10-01

    Mach reflection offers possibilities for generating planar, supported shocks at higher pressures than are practical even with laser ablation. We have studied the formation of Mach waves by algebraic solution and hydrocode simulation for drive pressures at much than reported previously, and for realistic equations of state. We predict that Mach reflection continues to occur as the drive pressure increases, and the pressure enhancement increases monotonically with drive pressure even though the ``enhancement spike'' characteristic of low-pressure Mach waves disappears. The growth angle also increases monotonically with pressure, so a higher drive pressure seems always to be an advantage. However, there are conditions where the Mach wave is perturbed by reflections. We have performed trial experiments at the Omega facility, using a laser-heated halfraum to induce a Mach wave in a polystyrene cone. Pulse length and energy limitations meant that the drive was not maintained long enough to fully support the shock, but the results indicated a Mach wave of 25-30 TPa from a drive pressure of 5-6 TPa, consistent with simulations. A similar configuration should be tested at the NIF, and a Z-pinch driven configuration may be possible. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  2. Looking into the future: An inward bias in aesthetic experience driven only by gaze cues.

    Science.gov (United States)

    Chen, Yi-Chia; Colombatto, Clara; Scholl, Brian J

    2018-07-01

    The inward bias is an especially powerful principle of aesthetic experience: In framed images (e.g. photographs), we prefer peripheral figures that face inward (vs. outward). Why does this bias exist? Since agents tend to act in the direction in which they are facing, one intriguing possibility is that the inward bias reflects a preference to view scenes from a perspective that will allow us to witness those predicted future actions. This account has been difficult to test with previous displays, in which facing direction is often confounded with either global shape profiles or the relative locations of salient features (since e.g. someone's face is generally more visually interesting than the back of their head). But here we demonstrate a robust inward bias in aesthetic judgment driven by a cue that is socially powerful but visually subtle: averted gaze. Subjects adjusted the positions of people in images to maximize the images' aesthetic appeal. People with direct gaze were not placed preferentially in particular regions, but people with averted gaze were reliably placed so that they appeared to be looking inward. This demonstrates that the inward bias can arise from visually subtle features, when those features signal how future events may unfold. Copyright © 2018. Published by Elsevier B.V.

  3. Design and Experiment of a Solder Paste Jetting System Driven by a Piezoelectric Stack

    Directory of Open Access Journals (Sweden)

    Shoudong Gu

    2016-06-01

    Full Text Available To compensate for the insufficiency and instability of solder paste dispensing and printing that are used in the SMT (Surface Mount Technology production process, a noncontact solder paste jetting system driven by a piezoelectric stack based on the principle of the nozzle-needle-system is introduced in this paper, in which a miniscule gap exists between the nozzle and needle during the jetting process. Here, the critical jet ejection velocity is discussed through theoretical analysis. The relations between ejection velocity and needle structure, needle velocity, and nozzle diameter were obtained by FLUENT software. Then, the prototype of the solder paste jetting system was fabricated, and the performance was verified by experiments. The effects of the gap between nozzle and needle, the driving voltage, and the nozzle diameter on the jetting performance and droplet diameter were obtained. Solder paste droplets 0.85 mm in diameter were produced when the gap between the nozzle and needle was adjusted to 10 μm, the driving voltage to 80 V, the nozzle diameter to 0.1 mm, and the variation of the droplet diameter was within ±3%.

  4. Laser Doppler vibrometry experiment on a piezo-driven slot synthetic jet in water

    Directory of Open Access Journals (Sweden)

    Broučková Zuzana

    2015-01-01

    Full Text Available The present study deals with a slot synthetic jet (SJ issuing from an actuator into quiescent surroundings and driven by a piezoceramic transducer. The actuator slot width was 0.36 mm, with a drive frequency proposed near the theoretical natural frequency of the actuator. The working fluid was water at room temperature. The present experiments used flow visualization (a laser-induced fluorescence technique and laser Doppler vibrometry methods. Flow visualization was used to identify SJ formation, to demonstrate its function, and to estimate SJ velocity. Laser Doppler vibrometry was used to quantify diaphragm displacement and refine operating parameters. Phase averaging yielded a spatial and temporal diaphragm deflection during the actuation period. Taking incompressibility and continuity into consideration, the velocity in the actuator slot and the Reynolds number of the SJ were evaluated as 0.21 m/s and 157, respectively. The present results confirmed a SJ actuator function at the resonance frequency of approximately 46 Hz, which corresponds closely with the theoretical evaluation. The laser Doppler vibrometry results corresponded closely with an estimation of SJ velocity by the present flow visualization.

  5. Optimization of current waveform tailoring for magnetically driven isentropic compression experiments

    Energy Technology Data Exchange (ETDEWEB)

    Waisman, E. M.; Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Cuneo, M. E.; Haill, T. A.; Davis, J.-P.; Brown, J. L.; Seagle, C. T. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Spielman, R. B. [Idaho State University, Pocatello, Idaho 83201 (United States)

    2016-06-15

    The Thor pulsed power generator is being developed at Sandia National Laboratories. The design consists of up to 288 decoupled and transit time isolated capacitor-switch units, called “bricks,” that can be individually triggered to achieve a high degree of pulse tailoring for magnetically driven isentropic compression experiments (ICE) [D. B. Reisman et al., Phys. Rev. Spec. Top.–Accel. Beams 18, 090401 (2015)]. The connecting transmission lines are impedance matched to the bricks, allowing the capacitor energy to be efficiently delivered to an ICE strip-line load with peak pressures of over 100 GPa. Thor will drive experiments to explore equation of state, material strength, and phase transition properties of a wide variety of materials. We present an optimization process for producing tailored current pulses, a requirement for many material studies, on the Thor generator. This technique, which is unique to the novel “current-adder” architecture used by Thor, entirely avoids the iterative use of complex circuit models to converge to the desired electrical pulse. We begin with magnetohydrodynamic simulations for a given material to determine its time dependent pressure and thus the desired strip-line load current and voltage. Because the bricks are connected to a central power flow section through transit-time isolated coaxial cables of constant impedance, the brick forward-going pulses are independent of each other. We observe that the desired equivalent forward-going current driving the pulse must be equal to the sum of the individual brick forward-going currents. We find a set of optimal brick delay times by requiring that the L{sub 2} norm of the difference between the brick-sum current and the desired forward-going current be a minimum. We describe the optimization procedure for the Thor design and show results for various materials of interest.

  6. Stimulated scattering in laser driven fusion and high energy density physics experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yin, L., E-mail: lyin@lanl.gov; Albright, B. J.; Rose, H. A.; Montgomery, D. S.; Kline, J. L.; Finnegan, S. M.; Bergen, B.; Bowers, K. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kirkwood, R. K.; Milovich, J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-09-15

    In laser driven fusion and high energy density physics experiments, one often encounters a kλ{sub D} range of 0.15 < kλ{sub D} < 0.5, where stimulated Raman scattering (SRS) is active (k is the initial electron plasma wave number and λ{sub D} is the Debye length). Using particle-in-cell simulations, the SRS reflectivity is found to scale as ∼ (kλ{sub D}){sup −4} for kλ{sub D} ≳ 0.3 where electron trapping effects dominate SRS saturation; the reflectivity scaling deviates from the above for kλ{sub D} < 0.3 when Langmuir decay instability (LDI) is present. The SRS risk is shown to be highest for kλ{sub D} between 0.2 and 0.3. SRS re-scattering processes are found to be unimportant under conditions relevant to ignition experiments at the National Ignition Facility (NIF). Large-scale simulations of the hohlraum plasma show that the SRS wavelength spectrum peaks below 600 nm, consistent with most measured NIF spectra, and that nonlinear trapping in the presence of plasma gradients determines the SRS spectral peak. Collisional effects on SRS, stimulated Brillouin scattering (SBS), LDI, and re-scatter, together with three dimensional effects, are examined. Effects of collisions are found to include de-trapping as well as cross-speckle electron temperature variation from collisional heating, the latter of which reduces gain, introduces a positive frequency shift that counters the trapping-induced negative frequency shift, and affects SRS and SBS saturation. Bowing and breakup of ion-acoustic wavefronts saturate SBS and cause a dramatic, sharp decrease in SBS reflectivity. Mitigation of SRS and SBS in the strongly nonlinear trapping regime is discussed.

  7. Experience-driven formation of parts-based representations in a model of layered visual memory

    Directory of Open Access Journals (Sweden)

    Jenia Jitsev

    2009-09-01

    Full Text Available Growing neuropsychological and neurophysiological evidence suggests that the visual cortex uses parts-based representations to encode, store and retrieve relevant objects. In such a scheme, objects are represented as a set of spatially distributed local features, or parts, arranged in stereotypical fashion. To encode the local appearance and to represent the relations between the constituent parts, there has to be an appropriate memory structure formed by previous experience with visual objects. Here, we propose a model how a hierarchical memory structure supporting efficient storage and rapid recall of parts-based representations can be established by an experience-driven process of self-organization. The process is based on the collaboration of slow bidirectional synaptic plasticity and homeostatic unit activity regulation, both running at the top of fast activity dynamics with winner-take-all character modulated by an oscillatory rhythm. These neural mechanisms lay down the basis for cooperation and competition between the distributed units and their synaptic connections. Choosing human face recognition as a test task, we show that, under the condition of open-ended, unsupervised incremental learning, the system is able to form memory traces for individual faces in a parts-based fashion. On a lower memory layer the synaptic structure is developed to represent local facial features and their interrelations, while the identities of different persons are captured explicitly on a higher layer. An additional property of the resulting representations is the sparseness of both the activity during the recall and the synaptic patterns comprising the memory traces.

  8. Results from Accelerator Driven TRIGA Reactor Experiments at The University of Texas at Austin

    International Nuclear Information System (INIS)

    O'Kelly, S.; Braisted, J.; Krause, M.; Welch, L.

    2008-01-01

    Accelerator Driven Transmutation of High-Level Waste (ATW) is one possible solution to the fuel reprocessing back-end problem for the disposal of high level waste such as minor actinides (Am, Np or Cm) and long-lived fission products. International programs continue to support research towards the eventual construction and operation of a proton accelerator driven spallation neutron source coupled to a subcritical 'neutron amplifier' for more efficient HLW transmutation. This project was performed under DOE AFCI Reactor-Accelerator Coupling Experiments (RACE). A 20 MeV Electron Linac was installed in the BP no 5 cave placing neutron source adjacent to an offset reactor core to maximize neutron coupling with available systems. Asymmetric neutron injection 'wasted' neutrons due to high leakage but sufficient neutrons were available to raise reactor power to ∼100 watts. The Linac provided approximately 100 mA but only 50% reached target. The Linac cooling system could not prevent overheating at frequencies over 200 Hz. The Linac electron beam had harmonics of primary frequency and periodic low frequency pulse intensity changes. Neutron detection using fission chambers in current mode eliminated saturation dead time and produced better sensitivity. The Operation of 'dual shielded' fission chambers reduced electron noise from linac. Benchmark criticality calculation using start-up data showed that the MCNPX model overestimates reactivity. TRIGA core was loaded to just slightly supercritical by adding graphite elements and measuring reactivity of $0.037. MCNPX modeled TRIGA core with and without graphite to arrive at 'true' measured subcritical multiplication of 0.998733± 0.00069. Thus, Alpha for the UT-RACE TRIGA core was approximately 155.99 s -1 . The Stochastic Feynman-Alpha Method (SFM) accuracy was evaluated during transients and reactivity changes. SFM was shown to be a potential real-time method of reactivity determination in future ADSS but requires stable

  9. Anomalous heating and plasmoid formation in pulsed power driven magnetic reconnection experiments

    Science.gov (United States)

    Hare, Jack

    2017-10-01

    Magnetic reconnection is an important process occurring in various plasma environments, including high energy density plasmas. In this talk we will present results from a recently developed magnetic reconnection platform driven by the MAGPIE pulsed power generator (1 MA, 250 ns) at Imperial College London. In these experiments, supersonic, sub-Alfvénic plasma flows collide, bringing anti-parallel magnetic fields into contact and producing a well-defined, elongated reconnection layer. This layer is long-lasting (>200 ns, > 10 hydrodynamic flow times) and is diagnosed using a suite of high resolution, spatially and temporally resolved diagnostics which include laser interferometry, Thomson scattering and Faraday rotation imaging. We observe significant heating of the electrons and ions inside the reconnection layer, and calculate that the heating must occur on time-scales far faster than can be explained by classical mechanisms. Possible anomalous mechanisms include in-plane electric fields caused by two-fluid effects, and enhanced resistivity and viscosity caused by kinetic turbulence. We also observe the repeated formation of plasmoids in the reconnection layer, which are ejected outwards along the layer at super-Alfvénic velocities. The O-point magnetic field structure of these plasmoids is determined using in situ magnetic probes, and these plasmoids could also play a role in the anomalous heating of the electrons and ions. In addition, we present further modifications to this experimental platform which enable us to study asymmetric reconnection or measure the out-of-plane magnetic field inside the plasmoids. This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) Grant No. EP/N013379/1, and by the U.S. Department of Energy (DOE) Awards No. DE-F03-02NA00057 and No. DE-SC-0001063.

  10. The TARC experiment (PS211): neutron-driven nuclear transmutation by adiabatic resonance crossing

    International Nuclear Information System (INIS)

    Revol, J.P.; Arnould, H.; Bompas, C.A.

    1999-01-01

    The main purpose of the TARC experiment is to demonstrate the possibility of using Adiabatic Resonance Crossing (ARC) to destroy efficiently Long-Lived Fission Fragments (LLFFs) in accelerator-driven systems and to validate a new simulation developed in the framework of the Energy Amplifier programme. An experimental set-up was installed in a CERN PS beam line to study how neutrons produced by spallation at relatively high energy (E n ≥1 MeV) slow down quasi adiabatically with almost flat isolethargic energy distribution and reach the capture resonance energy of an element to be transmuted where they will have a high probability of being captured. Precision measurements of energy and space distributions of spallation neutrons (using 2.5 GeV/c and 3.5 GeV/c protons) slowing down in a 3.3 m x 3.3 m x 3 m lead volume and of neutron capture rates of LLFFs 99 Tc, 129 I, and several other elements were performed. An appropriate formalism and appropriate computational tools necessary for the analysis and understanding of the data were developed and validated in detail. Our direct experimental observation of ARC demonstrates the possibility to destroy, in a parasitic mode, outside the Energy Amplifier core, large amounts of 99 Tc or 129 I at a rate exceeding the production rate, thereby making it practical to reduce correspondingly the existing stockpile of LLFFs. In addition, TARC opens up new possibilities for radioactive isotope production as an alternative to nuclear reactors, in particular for medical applications, as well as new possibilities for neutron research and industrial applications. (orig.)

  11. Using the computer-driven VR environment to promote experiences of natural world immersion

    Science.gov (United States)

    Frank, Lisa A.

    2013-03-01

    In December, 2011, over 800 people experienced the exhibit, :"der"//pattern for a virtual environment, created for the fully immersive CAVETM at the University of Wisconsin-Madison. This exhibition took my nature-based photographic work and reinterpreted it for virtual reality (VR).Varied responses such as: "It's like a moment of joy," or "I had to see it twice," or "I'm still thinking about it weeks later" were common. Although an implied goal of my 2D artwork is to create a connection that makes viewers more aware of what it means to be a part of the natural world, these six VR environments opened up an unexpected area of inquiry that my 2D work has not. Even as the experience was mediated by machines, there was a softening at the interface between technology and human sensibility. Somehow, for some people, through the unlikely auspices of a computer-driven environment, the project spoke to a human essence that they connected with in a way that went beyond all expectations and felt completely out of my hands. Other interesting behaviors were noted: in some scenarios some spoke of intense anxiety, acrophobia, claustrophobia-even fear of death when the scene took them underground. These environments were believable enough to cause extreme responses and disorientation for some people; were fun, pleasant and wonder-filled for most; and were liberating, poetic and meditative for many others. The exhibition seemed to promote imaginative skills, creativity, emotional insight, and environmental sensitivity. It also revealed the CAVETM to be a powerful tool that can encourage uniquely productive experiences. Quite by accident, I watched as these nature-based environments revealed and articulated an essential relationship between the human spirit and the physical world. The CAVETM is certainly not a natural space, but there is clear potential to explore virtual environments as a path to better and deeper connections between people and nature. We've long associated contact

  12. Reducing cognitive load in the chemistry laboratory by using technology-driven guided inquiry experiments

    Science.gov (United States)

    Hubacz, Frank, Jr.

    The chemistry laboratory is an integral component of the learning experience for students enrolled in college-level general chemistry courses. Science education research has shown that guided inquiry investigations provide students with an optimum learning environment within the laboratory. These investigations reflect the basic tenets of constructivism by engaging students in a learning environment that allows them to experience what they learn and to then construct, in their own minds, a meaningful understanding of the ideas and concepts investigated. However, educational research also indicates that the physical plant of the laboratory environment combined with the procedural requirements of the investigation itself often produces a great demand upon a student's working memory. This demand, which is often superfluous to the chemical concept under investigation, creates a sensory overload or extraneous cognitive load within the working memory and becomes a significant obstacle to student learning. Extraneous cognitive load inhibits necessary schema formation within the learner's working memory thereby impeding the transfer of ideas to the learner's long-term memory. Cognitive Load Theory suggests that instructional material developed to reduce extraneous cognitive load leads to an improved learning environment for the student which better allows for schema formation. This study first compared the cognitive load demand, as measured by mental effort, experienced by 33 participants enrolled in a first-year general chemistry course in which the treatment group, using technology based investigations, and the non-treatment group, using traditional labware, investigated identical chemical concepts on five different exercises. Mental effort was measured via a mental effort survey, a statistical comparison of individual survey results to a procedural step count, and an analysis of fourteen post-treatment interviews. Next, a statistical analysis of achievement was

  13. Capillary-Driven Heat Transfer Experiment: Keeping It Cool in Space

    Science.gov (United States)

    Lekan, Jack F.; Allen, Jeffrey S.

    1998-01-01

    Capillary-pumped loops (CPL's) are devices that are used to transport heat from one location to another--specifically to transfer heat away from something. In low-gravity applications, such as satellites (and possibly the International Space Station), CPL's are used to transfer heat from electrical devices to space radiators. This is accomplished by evaporating one liquid surface on the hot side of the CPL and condensing the vapor produced onto another liquid surface on the cold side. Capillary action, the phenomenon that causes paper towels to absorb spilled liquids, is used to "pump" the liquid back to the evaporating liquid surface (hot side) to complete the "loop." CPL's require no power to operate and can transfer heat over distances as large as 30 ft or more. Their reliance upon evaporation and condensation to transfer heat makes them much more economical in terms of weight than conventional heat transfer systems. Unfortunately, they have proven to be unreliable in space operations, and the explanation for this unreliability has been elusive. The Capillary-Driven Heat Transfer (CHT) experiment is investigating the fundamental fluid physics phenomena thought to be responsible for the failure of CPL's in low-gravity operations. If the failure mechanism can be identified, then appropriate design modifications can be developed to make capillary phase-change heat-transport devices a more viable option in space applications. CHT was conducted onboard the Space Shuttle Columbia during the first Microgravity Science Laboratory (MSL-1) mission, STS-94, which flew from July 1 to 17, 1997. The CHT glovebox investigation, which was conceived by Dr. Kevin Hallinan and Jeffrey Allen of the University of Dayton, focused on studying the dynamics associated with the heating and cooling at the evaporating meniscus within a capillary phase-change device in a low-gravity environment. The CHT experimental hardware was designed by a small team of engineers from Aerospace Design

  14. Assessing the existence of non-LTE behavior in aluminum K-shell diagnostic lines from dynamic hohlraum driven experiments

    International Nuclear Information System (INIS)

    Sherrill, M E

    2015-01-01

    We describe in this work a study designed to obtain insight into the sensitivity of foil targets driven out of local thermodynamic equilibrium (LTE) by an idealized dynamic hohlraum during its brightest phase. This work is motivated by a perceived over-prediction of the plasma temperature by current LTE spectral modeling of opacity experiments performed by Bailey et al at the Sandia Z facility. Although several aspects of this modeling study parallel the SNL/LANL opacity experiments, this work is primarily intended to gain insight into radiatively over-driven systems. The results from this idealized study suggest that a non-LTE population distribution with qualities similar to an LTE distribution at higher material temperatures are possible, and therefore support a further theoretical investigation with experimental parameters. (special issue paper)

  15. Battery-Powered RF Pre-Ionization System for the Caltech Magnetohydrodynamically-Driven Jet Experiment: RF Discharge Properties and MHD-Driven Jet Dynamics

    Science.gov (United States)

    Chaplin, Vernon H.

    This thesis describes investigations of two classes of laboratory plasmas with rather different properties: partially ionized low pressure radiofrequency (RF) discharges, and fully ionized high density magnetohydrodynamically (MHD)-driven jets. An RF pre-ionization system was developed to enable neutral gas breakdown at lower pressures and create hotter, faster jets in the Caltech MHD-Driven Jet Experiment. The RF plasma source used a custom pulsed 3 kW 13.56 MHz RF power amplifier that was powered by AA batteries, allowing it to safely float at 4-6 kV with the cathode of the jet experiment. The argon RF discharge equilibrium and transport properties were analyzed, and novel jet dynamics were observed. Although the RF plasma source was conceived as a wave-heated helicon source, scaling measurements and numerical modeling showed that inductive coupling was the dominant energy input mechanism. A one-dimensional time-dependent fluid model was developed to quantitatively explain the expansion of the pre-ionized plasma into the jet experiment chamber. The plasma transitioned from an ionizing phase with depressed neutral emission to a recombining phase with enhanced emission during the course of the experiment, causing fast camera images to be a poor indicator of the density distribution. Under certain conditions, the total visible and infrared brightness and the downstream ion density both increased after the RF power was turned off. The time-dependent emission patterns were used for an indirect measurement of the neutral gas pressure. The low-mass jets formed with the aid of the pre-ionization system were extremely narrow and collimated near the electrodes, with peak density exceeding that of jets created without pre-ionization. The initial neutral gas distribution prior to plasma breakdown was found to be critical in determining the ultimate jet structure. The visible radius of the dense central jet column was several times narrower than the axial current channel

  16. UV laser-driven shock-wave experiments at ultrahigh-pressures up to 5 TPa

    Energy Technology Data Exchange (ETDEWEB)

    Cottet, F.; Hallouin, M.; Romain, J.P. (GRECO ILM, Laboratoire d' Enegetique et Detonique, ENSMA, 86 - Poitiers (France)); Fabbro, R.; Faral, B. (GRECO ILM, Laboratoire de Physique des Milieux Ionises, Ecole Polytechnique, 91 - Palaiseau (France))

    1984-11-01

    Laser-driven shock pressures up to 5 TPa at 0.26 ..mu..m wavelenth have been evaluated from measurements of shock velocity through thin metallic foils (Al, Au, Cu) by streak camera records of shock luminosity at the near face of the foil.

  17. UV laser-driven shock-wave experiments at ultrahigh-pressures up to 5 TPa

    International Nuclear Information System (INIS)

    Cottet, F.; Hallouin, M.; Romain, J.P.; Fabbro, R.; Faral, B.

    1984-01-01

    Laser-driven shock pressures up to 5 TPa at 0.26 μm wavelenth have been evaluated from measurements of shock velocity through thin metallic foils (Al, Au, Cu) by streak camera records of shock luminosity at the near face of the foil

  18. An experience report on ERP effort estimation driven by quality requirements

    NARCIS (Netherlands)

    Erasmus, Pierre; Daneva, Maya; Schockert, Sixten

    2015-01-01

    Producing useful and accurate project effort estimates is highly dependable on the proper definition of the project scope. In the ERP service industry, the scope of an ERP service project is determined by desired needs which are driven by certain quality attributes that the client expects to be

  19. Experiences in Teaching a Graduate Course on Model-Driven Software Development

    Science.gov (United States)

    Tekinerdogan, Bedir

    2011-01-01

    Model-driven software development (MDSD) aims to support the development and evolution of software intensive systems using the basic concepts of model, metamodel, and model transformation. In parallel with the ongoing academic research, MDSD is more and more applied in industrial practices. After being accepted both by a broad community of…

  20. Quality Challenges in Transnational Higher Education under Profit-Driven Motives: The Vietnamese Experience

    Science.gov (United States)

    Nhan, Thi Thuy; Nguyen, Huu Cuong

    2018-01-01

    Among educational practices in the era of globalisation, developing countries are emerging with diverse representations of transnational collaboration. This paper investigates the operation and regulation of joint programs in Vietnam as a case study of higher education under the impact of profit-driven motives. It first reviews the trends,…

  1. Estimation of the sub-criticality of the sodium-cooled fast reactor Monju using the modified neutron source multiplication method

    International Nuclear Information System (INIS)

    Truchet, G.; Van Rooijen, W. F. G.; Shimazu, Y.; Yamaguchi, K.

    2012-01-01

    The Modified Neutron Source Method (MNSM) is applied to the Monju reactor. This static method to estimate sub-criticality has already given good results on commercial Pressurized Water Reactors. The MNSM consists both in the extraction of the fundamental mode seen by a detector to avoid the effect of higher modes near sources, and the correction of flux distortion effects due to control rod movement. Among Monju's particularities that have a big influence on MNSM factors are: the presence of two californium sources and the position of the detector which is located far from the core outside of the reactor vessel. The importance of spontaneous fission and (α, n) reactions which have increased during the shutdown period of 15 years will also be discussed. The relative position of detectors and sources deeply affect the correction factors in some regions. In order to evaluate the detector count rate, an analytical propagation has been conducted from the reactor vessel. For two subcritical states, an estimation of the reactivity has been made and compared to experimental data obtained in the restart experiments at Monju (2010). (authors)

  2. LANL sunnyside experiment: Study of neutron production in accelerator-driven targets

    International Nuclear Information System (INIS)

    Morgan, G.; Butler, G.; Cappiello, M.; Carius, S.; Daemen, L.; DeVolder, B.; Frehaut, J.; Goulding, C.; Grace, R.; Green, R.; Lisowski, P.; Littleton, P.; King, J.; King, N.; Prael, R.; Stratton, T.; Turner, S.; Ullmann, J.; Venneri, F.; Yates, M.

    1995-01-01

    Measurements have been made of the neutron production in prototypic targets for accelerator driven systems. Studies were conducted on four target assemblies containing lead, lithium, tungsten, and a thorium-salt mixture. Integral data on total neutron production were obtained as well as more differential data on neutron leakage and neutron flux profiles in the blanket/moderator region. Data analysis on total neutron production is complete and shows excellent agreement with calculations using the LAHET/MCNP code system

  3. LANL sunnyside experiment: Study of neutron production in accelerator-driven targets

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, G.; Butler, G.; Cappiello, M. [Los Alamos National Laboratory, NM (United States)] [and others

    1995-10-01

    Measurements have been made of the neutron production in prototypic targets for accelerator driven systems. Studies were conducted on four target assemblies containing lead, lithium, tungsten, and a thorium-salt mixture. Integral data on total neutron production were obtained as well as more differential data on neutron leakage and neutron flux profiles in the blanket/moderator region. Data analysis on total neutron production is complete and shows excellent agreement with calculations using the LAHET/MCNP code system.

  4. Experiences with vacuum type air-driven centrifuge for use in short nuclear lifetime measurements

    International Nuclear Information System (INIS)

    Khan, N.A.; Ahmed, M.

    1977-10-01

    The design, construction and performance of an improved vacuum type air-driven centrifuge having rotors of various material and radii are discusses. The centrifuge rotor is self-balancing and with the titanium rotors of 19 cm in diamter tip velocities upto 1.44 x 10 5 cms/sec have been achieved. The apparatus has been built for gamma ray resonance scattering studies and it is hoped to extend by about 25% the energy range of levels accessible by the rotor technique

  5. Treatment Wetland Aeration without Electricity? Lessons Learned from the First Experiment Using a Wind-Driven Air Pump

    Directory of Open Access Journals (Sweden)

    Johannes Boog

    2016-11-01

    Full Text Available Aerated treatment wetlands have become an increasingly recognized technology for treating wastewaters from domestic and various industrial origins. To date, treatment wetland aeration is provided by air pumps which require access to the energy grid. The requirement for electricity increases the ecological footprint of an aerated wetland and limits the application of this technology to areas with centralized electrical infrastructure. Wind power offers another possibility as a driver for wetland aeration, but its use for this purpose has not yet been investigated. This paper reports the first experimental trial using a simple wind-driven air pump to replace the conventional electric air blowers of an aerated horizontal subsurface flow wetland. The wind-driven air pump was connected to a two-year old horizontal flow aerated wetland which had been in continuous (24 h aeration since startup. The wind-driven aeration system functioned, however it was not specifically adapted to wetland aeration. As a result, treatment performance decreased compared to prior continuous aeration. Inconsistent wind speed at the site may have resulted in insufficient pressure within the aeration manifold, resulting in insufficient air supply to the wetland. This paper discusses the lessons learned during the experiment.

  6. Experiments with a pressure-driven Stirling refrigerator with flexible chambers

    Science.gov (United States)

    McFarlane, Patrick; Suire, Jonathan; Sen, Mihir; Semperlotti, Fabio

    2014-06-01

    We report on the design and experimental testing of a Stirling refrigerator that uses air as the working fluid, and where the conventional piston-cylinder assemblies are replaced by pressure-driven flexible chambers. The two chambers are periodically compressed by pneumatic actuators resulting in airflow through the regenerator and in a net temperature difference between the chambers. An experimental setup is used to investigate the performance of the refrigerator under different operating conditions with particular attention to actuation frequencies, driving pressure differences, and phase angles between the two inputs. The time constant of the temperature difference between the two chambers is determined, and the temperature difference is measured as a function of the system parameters. The results of several tests conducted under different operating conditions show that the refrigerating effect is very robust and allows good performance even for modulated inputs. The frequency response is radically different from that of a traditional motion-driven device. This work suggests that mechanical to thermal energy conversion devices based on this principle can be successfully powered by human motion.

  7. Data-driven CT protocol review and management—experience from a large academic hospital.

    Science.gov (United States)

    Zhang, Da; Savage, Cristy A; Li, Xinhua; Liu, Bob

    2015-03-01

    Protocol review plays a critical role in CT quality assurance, but large numbers of protocols and inconsistent protocol names on scanners and in exam records make thorough protocol review formidable. In this investigation, we report on a data-driven cataloging process that can be used to assist in the reviewing and management of CT protocols. We collected lists of scanner protocols, as well as 18 months of recent exam records, for 10 clinical scanners. We developed computer algorithms to automatically deconstruct the protocol names on the scanner and in the exam records into core names and descriptive components. Based on the core names, we were able to group the scanner protocols into a much smaller set of "core protocols," and to easily link exam records with the scanner protocols. We calculated the percentage of usage for each core protocol, from which the most heavily used protocols were identified. From the percentage-of-usage data, we found that, on average, 18, 33, and 49 core protocols per scanner covered 80%, 90%, and 95%, respectively, of all exams. These numbers are one order of magnitude smaller than the typical numbers of protocols that are loaded on a scanner (200-300, as reported in the literature). Duplicated, outdated, and rarely used protocols on the scanners were easily pinpointed in the cataloging process. The data-driven cataloging process can facilitate the task of protocol review. Copyright © 2015 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  8. The test of data driven TDC application in high energy physics experiment

    International Nuclear Information System (INIS)

    Liu Shubin; Guo Jianhua; Zhang Yanli; Zhao Long; An Qi

    2006-01-01

    In the high energy physics domain there is a trend to use integrated, high resolution, multi-hit time-digital-converter for time measurement, of which the data driven TDC is an important direction. Study on the method of how to test high performance TDC's characters and how to improve these characters will help us to select the proper TDC. The authors have studied the testing of a new high resolution TDC, which is planned to use in the third modification project of Beijing Spectrometer (BESIII). This paper introduces the test platform we built for the TDC, and the method by which we tested for nonlinearity, resolution, double pulse resolution characters, etc. The paper also gives the test results and introduces the compensation way to achieve a very high resolution (24.4 ps). (authors)

  9. Wave Driven Fast Ion Loss in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Fredrickson, E.D.; Cheng, C.Z.; Darrow, D.; Fu, G.; Gorelenkov, N.N.; Kramer, G.; Medley, S.S.; Menard, J.; Roquemore, L.; Stutman, D.; White, R.B.

    2003-01-01

    The study of fast ion instabilities in conventional aspect ratio tokamaks is motivated in large part by their potential to negatively impact the ignition threshold in fusion reactors by causing fast ion losses. Spherical tokamak's (ST), with intrinsically low magnetic fields, are particularly susceptible to fast ion driven instabilities. The 3.5 MeV alpha's from the D-T [deuterium-tritium] fusion reaction in proposed ST reactors will have velocities much higher than the Alfven speed. The Larmor radius of the fusion alphas, normalized to the plasma size, will also be larger than for conventional aspect ratio tokamak reactors. The resulting longer wavelengths of the *AE instabilities will be more effective in driving fast ion loss. The change in magnetic topology also influences the mode structure, as in the case of the Compressional Alfven Eigenmodes (CAE) seen on NSTX

  10. International Experiences and Frameworks to Support Country-Driven Low-Emissions Development

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, R.; Cochran, J.; Cox, S.

    2012-08-01

    Countries can use low-emission development strategies (LEDS) to advance sustainable development, promote private-sector growth, and reduce greenhouse gas emissions. This paper proposes a framework -- or support infrastructure -- to enable the efficient exchange of LEDS-related knowledge and technical assistance. Under the proposed framework, countries share LEDS-related resources via coordinating forums, 'knowledge platforms,' and networks of experts and investors. The virtual 'knowledge platforms' foster learning by allowing countries to communicate with each other and share technical reports, data, and analysis tools in support of LEDS development. Investing in all elements of the framework in an integrated fashion increases the efficacy of support for country-driven LEDS.

  11. Dynamic Simulation of the Water-steam System in Once-through Boilers - Sub-critical Power Boiler Case -

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seongil; Choi, Sangmin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2017-05-15

    The dynamics of a water-steam system in a once-through boiler was simulated based on the physics-based modeling approach, representing the system in response to large load change or scale disturbance simulations. The modeling considered the mass, energy conservation, and momentum equation in the water pipe and the focus was limited to the sub-critical pressure region. An evaporator tube modeling was validated against the reference data. A simplified boiler system consisting of economizer, evaporator, and superheater was constructed to match a 500 MW power boiler. The dynamic response of the system following a disturbance was discussed along with the quantitative response characteristics. The dynamic response of the boiler system was further evaluated by checking the case of an off-design point operation of the feedwater-to-fuel supply ratio. The results re-emphasized the significance of controlling the feedwater-to-fuel supply ratio and additional design requirements of the water-steam separator and spray attemperator.

  12. Dynamic Simulation of the Water-steam System in Once-through Boilers - Sub-critical Power Boiler Case -

    International Nuclear Information System (INIS)

    Kim, Seongil; Choi, Sangmin

    2017-01-01

    The dynamics of a water-steam system in a once-through boiler was simulated based on the physics-based modeling approach, representing the system in response to large load change or scale disturbance simulations. The modeling considered the mass, energy conservation, and momentum equation in the water pipe and the focus was limited to the sub-critical pressure region. An evaporator tube modeling was validated against the reference data. A simplified boiler system consisting of economizer, evaporator, and superheater was constructed to match a 500 MW power boiler. The dynamic response of the system following a disturbance was discussed along with the quantitative response characteristics. The dynamic response of the boiler system was further evaluated by checking the case of an off-design point operation of the feedwater-to-fuel supply ratio. The results re-emphasized the significance of controlling the feedwater-to-fuel supply ratio and additional design requirements of the water-steam separator and spray attemperator.

  13. To the question of definition of fissile material mass and neutron multiplication in deep sub-critical systems

    International Nuclear Information System (INIS)

    Dulin, V.V.

    2006-01-01

    A method of determination neutrons multiplication in deep sub-critical multiplying media has been developed. It is based on a modified of Rossi - alpha method. It will consist in use of integral on time (a method of the areas) from correlated parts of distribution and integral in area, independent of time a part of distribution (area of a constant background). It allows to spend the calculated analysis, using the integrated equation on time for a neutrons flux and to not use representation of point kinetic model. A calculation spatially-correlation factor the adjoint (relative the detector count rate) inhomogeneous equation is used. Its calculation takes into account fission both in multiplying media and in a spontaneous neutron source. Measurements with plutonium-steel and uranium-steel blocks, and blocks from uranium and plutonium dioxide of different enrichment are have been carried out. The measured values of neutrons multiplication in a range 1.03-1.82 will be well coordinated to results of calculations. The question on an opportunity of definition of weight of the measured blocks of fissile material is considered [ru

  14. Why public health services? Experiences from profit-driven health care reforms in Sweden.

    Science.gov (United States)

    Dahlgren, Göran

    2014-01-01

    Market-oriented health care reforms have been implemented in the tax-financed Swedish health care system from 1990 to 2013. The first phase of these reforms was the introduction of new public management systems, where public health centers and public hospitals were to act as private firms in an internal health care market. A second phase saw an increase of tax-financed private for-profit providers. A third phase can now be envisaged with increased private financing of essential health services. The main evidence-based effects of these markets and profit-driven reforms can be summarized as follows: efficiency is typically reduced but rarely increased; profit and tax evasion are a drain on resources for health care; geographical and social inequities are widened while the number of tax-financed providers increases; patients with major multi-health problems are often given lower priority than patients with minor health problems; opportunities to control the quality of care are reduced; tax-financed private for-profit providers facilitate increased private financing; and market forces and commercial interests undermine the power of democratic institutions. Policy options to promote further development of a nonprofit health care system are highlighted.

  15. Design and experiments of a linear piezoelectric motor driven by a single mode.

    Science.gov (United States)

    Liu, Zhen; Yao, Zhiyuan; Li, Xiang; Fu, Qianwei

    2016-11-01

    In this contribution, we propose a novel linear piezoelectric motor with a compact stator that is driven by a single mode. The linear piezoelectric motor can realize bidirectional motion by changing the vibration modes of the stator. Finite element analysis is performed to determine the required vibration mode of the stator and obtain the optimal stator structure and dimensions. Furthermore, the trajectories of the driving foot are analyzed with and without consideration of the mechanical contact with the slider. It is shown that the trajectory of the driving foot is an oblique line when disregarding the contact, and the trajectory becomes an oblique ellipse while taking into account the contact. Finally, a prototype of the motor is fabricated based on the results of finite element analysis. The optimization results show that the motor reaches its maximum thrust force of 4.0 kg, maximum thrust-weight ratio of 33.3, maximum unloaded velocity of 385 mm/s under the excitation of Mode-B, and maximum unloaded velocity of 315 mm/s under the excitation of Mode-L.

  16. Accelerator Studies on a possible Experiment on Proton-Driven Plasma Wakefields at CERN

    CERN Document Server

    Assmann, R W; Fartoukh, S; Geschonke, G; Goddard, B; Hessler, C; Hillenbrand, S; Meddahi, M; Roesler, S; Zimmermann, F; Caldwell, A; Muggli, P; Xia, G

    2011-01-01

    There has been a proposal by Caldwell et al to use proton beams as drivers for high energy linear colliders. An experimental test with CERN’s proton beams is being studied. Such a test requires a transfer line for transporting the beam to the experiment, a focusing section for beam delivery into the plasma, the plasma cell and a downstream diagnostics and dump section. The work done at CERN towards the conceptual layout and design of such a test area is presented. A possible development of such a test area into a CERN test facility for high-gradient acceleration experiments is discussed.

  17. Interaction of pressure and momentum driven flows with thin porous media: Experiments and modeling

    Science.gov (United States)

    Naaktgeboren, Christian

    Flow interaction with thin porous media arise in a variety of natural and man-made settings. Examples include flow through thin grids in electronics cooling, and NOx emissions reduction by means of ammonia injection grids, pulsatile aquatic propulsion with complex trailing anatomy (e.g., jellyfish with tentacles) and microbursts from thunderstorm activity over dense vegetation, unsteady combustion in or near porous materials, pulsatile jet-drying of textiles, and pulsed jet agitation of clothing for trace contaminant sampling. Two types of interactions with thin porous media are considered: (i) forced convection or pressure-driven flows, where fluid advection is maintained by external forces, and (ii) inertial or momentum-driven flows, in which fluid motion is generated but not maintained by external forces. Forced convection analysis through thin permeable media using a porous continuum approach requires the knowledge of porous medium permeability and form coefficients, K and C, respectively, which are defined by the Hazen-Dupuit-Darcy (HDD) equation. Their determination, however, requires the measurement of the pressure-drop per unit of porous medium length. The pressure-drop caused by fluid entering and exiting the porous medium, however, is not related to the porous medium length. Hence, for situations in which the inlet and outlet pressure-drops are not negligible, e.g., for short porous media, the definition of Kand C via the HDD equation becomes ambiguous. This aspect is investigated analytically and numerically using the flow through a restriction in circular pipe and parallel plates channels as preliminary models. Results show that inlet and outlet pressure-drop effects become increasingly important when the inlet and outlet fluid surface fraction φ decreases and the Reynolds number Re increases for both laminar and turbulent flow regimes. A conservative estimate of the minimum porous medium length beyond which the core pressure-drop predominates over the

  18. Measuring implosion velocities in experiments and simulations of laser-driven cylindrical implosions on the OMEGA laser

    Science.gov (United States)

    Hansen, E. C.; Barnak, D. H.; Betti, R.; Campbell, E. M.; Chang, P.-Y.; Davies, J. R.; Glebov, V. Yu; Knauer, J. P.; Peebles, J.; Regan, S. P.; Sefkow, A. B.

    2018-05-01

    Laser-driven magnetized liner inertial fusion (MagLIF) on OMEGA involves cylindrical implosions, a preheat beam, and an applied magnetic field. Initial experiments excluded the preheat beam and magnetic field to better characterize the implosion. X-ray self-emission as measured by framing cameras was used to determine the shell trajectory. The 1D code LILAC was used to model the central region of the implosion, and results were compared to 2D simulations from the HYDRA code. Post-processing of simulation output with SPECT3D and Yorick produced synthetic x-ray images that were used to compare the simulation results with the x-ray framing camera data. Quantitative analysis shows that higher measured neutron yields correlate with higher implosion velocities. The future goal is to further analyze the x-ray images to characterize the uniformity of the implosions and apply these analysis techniques to integrated laser-driven MagLIF shots to better understand the effects of preheat and the magnetic field.

  19. Data report for ROSA-IV LSTF gravity-driven safety injection experiment run SB-CL-27

    International Nuclear Information System (INIS)

    Yonomoto, Taisuke; Saitou, Seishi; Kuroda, Takeshi

    1994-03-01

    Experimental data are presented for the passive injection test, Run SB-CL-27, conducted at the ROSA-IV Large Scale Test Facility (LSTF) on September 17, 1992. This experiment simulated thermal-hydraulic behavior of a gravity-driven, passive safety injection system during a small-break loss-of-coolant accident (LOCA) in a pressurized water reactor (PWR). The injection system consisted of a gravity-driven injection tank, located above the reactor vessel, with connecting lines. The tank was initially filled with water of room temperature at the same pressure as the pressurizer. The connecting lines to the cold leg and to the vessel downcomer were opened at the test initiation. Then, a natural circulation flow developed in the loop which was formed by these lines and the injection tank. The hot water in the cold leg circulated into the upper part of tank and accumulated there causing a significant thermal stratification. This thermal stratification prevented direct-contact condensation of steam from occurring during the subsequent tank drain-down phase. Therefore, no condensation-induced depressurization of the tank, affecting adversely the injection performance, occurred. (author)

  20. Dynamic Data Driven Experiment Control Coordinated with Anisotropic Elastic Material Characterization

    Science.gov (United States)

    John G. Michopoulos; Tomonari Furukawa; John C. Hermanson; Samuel G. Lambrakos

    2011-01-01

    The goal of this paper is to propose and demonstrate a multi level design optimization approach for the coordinated determination of a material constitutive model synchronously to the design of the experimental procedure needed to acquire the necessary data. The methodology achieves both online (real-time) and offline design of optimum experiments required for...

  1. Data-driven property verification of grey-box systems by Bayesian experiment design

    NARCIS (Netherlands)

    Haesaert, S.; Van den Hof, P.M.J.; Abate, A.

    2015-01-01

    A measurement-based statistical verification approach is developed for systems with partly unknown dynamics. These grey-box systems are subject to identification experiments which, new in this contribution, enable accepting or rejecting system properties expressed in a linear-time logic. We employ a

  2. Database of full-scale laboratory experiments on wave-driven sand transport processes

    NARCIS (Netherlands)

    van der Werf, Jebbe J.; Schretlen, Johanna Lidwina Maria; Ribberink, Jan S.; O'Donoghue, Tom

    2009-01-01

    A new database of laboratory experiments involving sand transport processes over horizontal, mobile sand beds under full-scale non-breaking wave and non-breaking wave-plus-current conditions is described. The database contains details of the flow and bed conditions, information on which quantities

  3. Understanding hospital meal experiences by means of participant-driven-photo-elicitation

    DEFF Research Database (Denmark)

    Justesen, Lise; Mikkelsen, Bent Egberg; Gyimóthy, Szilvia

    2013-01-01

    in an open-ended interview. Two inductive analytical approaches were selected to assess the patients’ reflections on their hospital meal experiences. First, the interview transcripts were analysed using the Semiotic Analysis approach using qualitative data analysis software NVivo 9. Second, the 91 produced...

  4. Development of X-ray tracer diagnostics for radiatively-driven ablator experiments

    International Nuclear Information System (INIS)

    MacFarlane, J.J.; Cohen, D.H.; Wang, P.; Moses, G.A.; Peterson, R.R.; Jaanimagi, P.A.; Langen, O.L.; Olson, R.E.; Murphy, T.J.; Magelssen, G.R.; Delamater, N.D.

    1999-01-01

    This report covers fiscal year 1998 of our ongoing project to develop tracer X-ray spectroscopic diagnostics for hohlraum environments. This effort focused on an experimental campaign carried out at OMEGA on 25--27 August 1998. This phase of the project heavily emphasized experimental design, diagnostic development, and target fabrication, as well as building up numerical models for the experiments. The spectral diagnostic under development involves using two thin (few 1000 Angstroem) mid-Z tracers in two witness plates mounted on the side of a hohlraum with the tracers' K a absorption features seen against an X-ray backlighter. The absorption data are used to sample the time-dependent, localized properties of each witness plate as a radiation wave ablates it. The experiments represented the first application of this diagnostic, in this case to side-by-side doped and undoped plastic to investigate the effects of capsule ablator dopants

  5. Photocathode driven linac at UCLA for FEL and plasma wakefield acceleration experiments

    International Nuclear Information System (INIS)

    Hartman, S.; Aghamir, F.; Barletta, W.; Cline, D.; Dodd, J.; Katsouleas, T.; Kolonko, J.; Park, S.; Pellegrini, C.; Rosenzweig, J.; Smolin, J.; Terrien, J.; Davis, J.; Hairapetian, G.; Joshi, C.; Luhmann, N. Jr.; McDermott, D.

    1991-01-01

    The UCLA compact 20-MeV/c electron linear accelerator is designed to produce a single electron bunch with a peak current of 200 A, an rms energy spread of 0.2% or less, and a short 1.2 picosecond rms pulse duration. The linac is also designed to minimize emittance growth down the beamline so as to obtain emittances of the order of 8πmm-mrad in the experimental region. The linac will feed two beamlines, the first will run straight into the undulator for FEL experiments while the second will be used for diagnostics, longitudinal bunch compression, and other electron beam experiments. Here the authors describe the considerations put into the design of the accelerating structures and the transport to the experimental areas

  6. Design and experiment of a human-limb driven, frequency up-converted electromagnetic energy harvester

    International Nuclear Information System (INIS)

    Halim, Miah A.; Cho, Hyunok; Park, Jae Y.

    2015-01-01

    Highlights: • A frequency up-converted miniaturized energy harvester, driven by hand-shaking. • Use of a freely movable ball conquers the inconvenience in resonance issue at frequencies below 10 Hz. • Can be implemented to hand-held and wearable devices through efficient power conditioning circuitry. - Abstract: We present a frequency up-converted electromagnetic energy harvester that generates significant power from human-limb motion (hand-shaking). Because the power generated by a vibration energy harvester is proportional to the operating frequency, the proposed energy harvester has been designed to up-convert the applied low-frequency vibration to a high-frequency vibration by mechanical impact. Upon excitation, a freely moveable ball (non-magnetic) within a cylindrical structure periodically hits two magnets suspended on two helical compression springs located at either ends of the cylinder, allowing these to vibrate with higher frequencies. The relative motion between the magnets and coils (wrapped around the outside of the cylinder) induces e.m.f. (voltage). High-frequency oscillators have been designed through the design parameters (i.e., frequency, spring stiffness, mechanical, and electrical damping), to minimize the power loss. A prototype was fabricated and tested both using a vibration exciter and by manual hand-shaking. The fabricated device showed non-resonant behavior during the vibration exciter test. At optimum load condition, the frequency up-converted generators (FUGs) delivered 0.84 mW and 0.96 mW of average power. A maximum 2.15 mW of average power was obtained from the device with series connected FUGs while it was mounted on a smart phone and was hand-shaken. The fabricated device exhibited 0.33 mW cm −3 of average power density, which is very high compared to the current state-of-the-art devices, indicating its ability in powering portable and wearable smart devices from extremely low frequency (∼5 Hz) vibration.

  7. A distributed real-time system for event-driven control and dynamic data acquisition on a fusion plasma experiment

    International Nuclear Information System (INIS)

    Sousa, J.; Combo, A.; Batista, A.; Correia, M.; Trotman, D.; Waterhouse, J.; Varandas, C.A.F.

    2000-01-01

    A distributed real-time trigger and timing system, designed in a tree-type topology and implemented in VME and CAMAC versions, has been developed for a magnetic confinement fusion experiment. It provides sub-microsecond time latencies for the transport of small data objects allowing event-driven discharge control with failure counteraction, dynamic pre-trigger sampling and event recording as well as accurate simultaneous triggers and synchronism on all nodes with acceptable optimality and predictability of timeliness. This paper describes the technical characteristics of the hardware components (central unit composed by one or more reflector crates, event and synchronism reflector cards, event and pulse node module, fan-out and fan-in modules) as well as software for both tests and integration on a global data acquisition system. The results of laboratory operation for several configurations and the overall performance of the system are presented and analysed

  8. Sodium source development for pulsed power driven, photopumped NA/NE x-ray laser experiments

    International Nuclear Information System (INIS)

    Burkhalter, P.G.; Cooperstein, G.; Mosher, D.; Ottinger, P.F.; Scherrer, V.E.; Stephanakis, S.J.; Young, F.C.; Hinshelwood, D.D.; Mehlman, G.; Welch, B.L.; Jones, W.D.

    1988-01-01

    A sodium plasma source is being developed for a resonant photopumping x-ray laser scheme in which the 11A 1s 2 - 1s2rho 1 P 1 line in heliumlike Na X is used to pump the Ne IX n=4 singlet level. In their experiment the NRL Gamble II generator is used to produce two z-pinch plasmas in a side-by-side geometry. The sodium plasma is produced on axis and conducts the full 1 MA machine current. A fraction of this current returns through a neon gas puff located 5 cm from the sodium. This separation is determined by the need to prevent the plasmas from mixing and the need to have each plasma's azimuthal magnetic field as symmetric as possible. A minimum separation is desirable to increase coupling efficiency. To improve the pump source, a more confined source of pure sodium involving a coaxial plasma gun is being developed. They are currently studying both the operation of this source on a test stand and implosions of the resulting plasma on Gamble II. In initial experiments aluminum is substituted for sodium. Test stand diagnostics include photodiodes, witness plates, and current monitors designed to investigate the early motion of the annular plasma. Results from test stand and Gamble II experiments with both aluminum and sodium, as well as sodium handling techniques, are presented

  9. Arctic research in the classroom: A teacher's experiences translated into data driven lesson plans

    Science.gov (United States)

    Kendrick, E. O.; Deegan, L.

    2011-12-01

    Incorporating research into high school science classrooms can promote critical thinking skills and provide a link between students and the scientific community. Basic science concepts become more relevant to students when taught in the context of research. A vital component of incorporating current research into classroom lessons is involving high school teachers in authentic research. The National Science Foundation sponsored Research Experience for Teachers (RET) program has inspired me to bring research to my classroom, communicate the importance of research in the classroom to other teachers and create lasting connections between students and the research community. Through my experiences as an RET at Toolik Field Station in Alaska, I have created several hands-on lessons and laboratory activities that are based on current arctic research and climate change. Each lesson uses arctic research as a theme for exemplifying basic biology concepts as well as increasing awareness of current topics such as climate change. For instance, data collected on the Kuparuk River will be incorporated into classroom activities that teach concepts such as primary production, trophic levels in a food chain and nutrient cycling within an ecosystem. Students will not only understand the biological concepts but also recognize the ecological implications of the research being conducted in the arctic. By using my experience in arctic research as a template, my students will gain a deeper understanding of the scientific process. I hope to create a crucial link of information between the science community and science education in public schools.

  10. Physics study of D-D/D-T neutron driven experimental subcritical assembly

    International Nuclear Information System (INIS)

    Sinha, Amar

    2015-01-01

    An experimental program to design and study external source driven subcritical assembly has been initiated at BARC. This program is aimed at understanding neutronic characteristics of accelerator driven system at low power level. In this series, a zero-power, sub-critical assembly driven by a D-D/D-T neutron generator has been developed. This system is modular in design and it is first in the series of subcritical assemblies being designed. The subcritical core consists of natural uranium fuel with high density polyethylene as moderator and beryllium oxide as reflector. The subcritical core is coupled to Purnima Neutron Generator. Preliminary experiments have been carried out for spatial flux measurement and reactivity estimation using pulsed neutron source (PNS) techniques. Further experiments are being planned to measure the reactivity and other kinetic parameters using noise methods. This facility would also be used for carrying out studies on effect of source importance and measurement of source multiplication factor k s and external neutron source efficiency φ* in great details. Some experiments with D-D and D-T neutrons have been presented. (author)

  11. Laser-Driven Hydrodynamic Experiments in the Turbulent Plasma Regime: from OMEGA to NIF

    International Nuclear Information System (INIS)

    Robey, H F; Miles, A R; Hansen, J F; Blue, B E; Drake, R P

    2003-01-01

    There is a great deal of interest in studying the evolution of hydrodynamic phenomena in high energy density plasmas that have transitioned beyond the initial phases of instability into an Ely developed turbulent state. Motivation for this study arises both in fusion plasmas as well as in numerous astrophysical applications where the understanding of turbulent mixing is essential. Double-shell ignition targets, for example, are subject to large growth of short wavelength perturbations on both surfaces of the high-Z inner shell. These perturbations, initiated by Richtmyer-Meshkov and Rayleigh-Taylor instabilities, can transition to a turbulent state and will lead to deleterious mixing of the cooler shell material with the hot burning fuel. In astrophysical plasmas, due to the extremely large scale, turbulent hydrodynamic mixing is also of wide-spread interest. The radial mixing that occurs in the explosion phase of core-collapse supernovae is an example that has received much attention in recent years and yet remains only poorly understood. In all of these cases, numerical simulation of the flow field is very difficult due to the large Reynolds number and corresponding wide range of spatial scales characterizing the plasma. Laboratory experiments on high energy density facilities that can access this regime are therefore of great interest. Experiments exploring the transition to turbulence that are currently being conducted on the Omega laser will be described. We will also discuss experiments being planned for the initial commissioning phases of the NIF as well as the enhanced experimental parameter space that will become available, as additional quads are made operational

  12. Conceptual design of a laser-plasma accelerator driven free-electron laser demonstration experiment

    International Nuclear Information System (INIS)

    Seggebrock, Thorben

    2015-01-01

    Up to now, short-wavelength free-electron lasers (FEL) have been systems on the scale of hundreds of meters up to multiple kilometers. Due to the advancements in laser-plasma acceleration in the recent years, these accelerators have become a promising candidate for driving a fifth-generation synchrotron light source - a lab-scale free-electron laser. So far, demonstration experiments have been hindered by the broad energy spread typical for this type of accelerator. This thesis addresses the most important challenges of the conceptual design for a first lab-scale FEL demonstration experiment using analytical considerations as well as simulations. The broad energy spread reduces the FEL performance directly by weakening the microbunching and indirectly via chromatic emittance growth, caused by the focusing system. Both issues can be mitigated by decompressing the electron bunch in a magnetic chicane, resulting in a sorting by energies. This reduces the local energy spread as well as the local chromatic emittance growth and also lowers performance degradations caused by the short bunch length. Moreover, the energy dependent focus position leads to a focus motion within the bunch, which can be synchronized with the radiation pulse, maximizing the current density in the interaction region. This concept is termed chromatic focus matching. A comparison shows the advantages of the longitudinal decompression concept compared to the alternative approach of transverse dispersion. When using typical laser-plasma based electron bunches, coherent synchrotron radiation and space-charge contribute in equal measure to the emittance growth during decompression. It is shown that a chicane for this purpose must not be as weak and long as affordable to reduce coherent synchrotron radiation, but that an intermediate length is required. Furthermore, the interplay of the individual concepts and components is assessed in a start-to-end simulation, confirming the feasibility of the

  13. Conceptual design of a laser-plasma accelerator driven free-electron laser demonstration experiment

    Energy Technology Data Exchange (ETDEWEB)

    Seggebrock, Thorben

    2015-07-08

    Up to now, short-wavelength free-electron lasers (FEL) have been systems on the scale of hundreds of meters up to multiple kilometers. Due to the advancements in laser-plasma acceleration in the recent years, these accelerators have become a promising candidate for driving a fifth-generation synchrotron light source - a lab-scale free-electron laser. So far, demonstration experiments have been hindered by the broad energy spread typical for this type of accelerator. This thesis addresses the most important challenges of the conceptual design for a first lab-scale FEL demonstration experiment using analytical considerations as well as simulations. The broad energy spread reduces the FEL performance directly by weakening the microbunching and indirectly via chromatic emittance growth, caused by the focusing system. Both issues can be mitigated by decompressing the electron bunch in a magnetic chicane, resulting in a sorting by energies. This reduces the local energy spread as well as the local chromatic emittance growth and also lowers performance degradations caused by the short bunch length. Moreover, the energy dependent focus position leads to a focus motion within the bunch, which can be synchronized with the radiation pulse, maximizing the current density in the interaction region. This concept is termed chromatic focus matching. A comparison shows the advantages of the longitudinal decompression concept compared to the alternative approach of transverse dispersion. When using typical laser-plasma based electron bunches, coherent synchrotron radiation and space-charge contribute in equal measure to the emittance growth during decompression. It is shown that a chicane for this purpose must not be as weak and long as affordable to reduce coherent synchrotron radiation, but that an intermediate length is required. Furthermore, the interplay of the individual concepts and components is assessed in a start-to-end simulation, confirming the feasibility of the

  14. Experiments on resonator concept of plasma wakefield accelerator driven by a train of relativistic electron bunches

    International Nuclear Information System (INIS)

    Kiselev, V.A.; Linnik, A.F.; Mirny, V. I; Onishchenko, I.N.; Uskov, V.V.

    2008-01-01

    The experimental installation was elaborated to increase plasma wakefield amplitude by means of using plasma resonator that allows all bunches of the train to participate in wakefield build-up contrary to waveguide case, in which due to group velocity effect only a part of the bunches participates. Experiments on plasma producing with resonant density, at which a coincidence of the plasma frequency and bunch repetition frequency is provided, are carried out. The first results of the measurements of beam energy loss on plasma wakefield excitation and energy gain by accelerated electrons are presented

  15. Theory of current-driven instability experiments in magnetic Taylor-Couette flows.

    Science.gov (United States)

    Rüdiger, Günther; Schultz, Manfred; Shalybkov, Dima; Hollerbach, Rainer

    2007-11-01

    We consider the linear stability of dissipative magnetic Taylor-Couette flow with imposed toroidal magnetic fields. The inner and outer cylinders can be either insulating or conducting; the inner one rotates, the outer one is stationary. The magnetic Prandtl number can be as small as 10(-5) , approaching realistic liquid-metal values. The magnetic field destabilizes the flow, except for radial profiles of B(phi)(R) close to the current-free solution. The profile with B(in)=B(out) (the most uniform field) is considered in detail. For weak fields the Taylor-Couette flow is stabilized, until for moderately strong fields the m=1 azimuthal mode dramatically destabilizes the flow again so that a maximum value for the critical Reynolds number exists. For sufficiently strong fields (as measured by the Hartmann number) the toroidal field is always unstable, even for the nonrotating case with Re=0 . The electric currents needed to generate the required toroidal fields in laboratory experiments are a few kA if liquid sodium is used, somewhat more if gallium is used. Weaker currents are needed for wider gaps, so a wide-gap apparatus could succeed even with gallium. The critical Reynolds numbers are only somewhat larger than the nonmagnetic values; hence such experiments would work with only modest rotation rates.

  16. Ion temperature gradient driven transport in a density modification experiment on the TFTR tokamak

    International Nuclear Information System (INIS)

    Horton, W.; Lindberg, D.; Kim, J.Y.; Dong, J.Q.; Hammett, G.W.; Scott, S.D.; Zarnstorff, M.C.; Hamaguchi, S.

    1991-07-01

    TFTR profiles from a supershot density-modification experiment are analyzed for their local and ballooning stability to toroidal η i -modes in order to understand the initially puzzling results showing no increase in X i when a pellet is used to produce an abrupt and large increase in the η i parameter. The local stability analysis assumes that k parallel = 1/qR and ignores the effects of shear, but makes no assumption on the magnitude of k parallel v ti /ω. The ballooning stability analysis determines a self-consistent linear spectrum of k parallel's including the effect of shear and toroidicity, but it expands in k parallel v ti /ω ≤ 1, which is a marginal assumption for this experiment. Nevertheless, the two approaches agree well and show that the mixing length estimate of the transport rate does not change appreciably during the density-modification and has a value close to or less than the observed X i , in contrast to most previous theories which predicted X i 's which were over an order-of-magnitude too large. However, we are still unable to explain the observed increase X i (r) with minor radius by adding the effects of the finite beta drift - MHD mode coupling, the slab-like mode, or the trapped electron response. The experimental tracking 0.2 e /X i i and trapped-electron driving mechanisms are operating. 4 refs., 5 figs., 5 tabs

  17. Chaotic advection at large Péclet number: Electromagnetically driven experiments, numerical simulations, and theoretical predictions

    International Nuclear Information System (INIS)

    Figueroa, Aldo; Meunier, Patrice; Villermaux, Emmanuel; Cuevas, Sergio; Ramos, Eduardo

    2014-01-01

    We present a combination of experiment, theory, and modelling on laminar mixing at large Péclet number. The flow is produced by oscillating electromagnetic forces in a thin electrolytic fluid layer, leading to oscillating dipoles, quadrupoles, octopoles, and disordered flows. The numerical simulations are based on the Diffusive Strip Method (DSM) which was recently introduced (P. Meunier and E. Villermaux, “The diffusive strip method for scalar mixing in two-dimensions,” J. Fluid Mech. 662, 134–172 (2010)) to solve the advection-diffusion problem by combining Lagrangian techniques and theoretical modelling of the diffusion. Numerical simulations obtained with the DSM are in reasonable agreement with quantitative dye visualization experiments of the scalar fields. A theoretical model based on log-normal Probability Density Functions (PDFs) of stretching factors, characteristic of homogeneous turbulence in the Batchelor regime, allows to predict the PDFs of scalar in agreement with numerical and experimental results. This model also indicates that the PDFs of scalar are asymptotically close to log-normal at late stages, except for the large concentration levels which correspond to low stretching factors

  18. Accelerator driven sub-critical systems for waste transmutation: co-operation and co-ordination in Europe and the role of the technical working group

    International Nuclear Information System (INIS)

    Salvatores, M.; Monti, S.

    2001-01-01

    The TWG under the chairmanship of Carlo Rubbia, enlarged from the three initial partners (France, Italy, Spain) to ten partners (Austria, Belgium, Finland, France, Germany, Italy, JRC, Portugal, Spain, Sweden), has worked to identify critical technical issues, R and D needs and a strategy in view of an ADS demonstration programme. A road map document is being prepared, and state of the art reports have been issued in Accelerator and Fuel and Fuel Processing Technologies. The TWG allows also a monitoring and harmonization of other European projects, like: the MEGAPIE project for the construction and operation of a 1 MWt Pb/Bi target in the SINQ installation in PSI-Switzerland; the proposal for a preliminary design study of an XADS; which will be both submitted to the second call of P and T within the 5. European Framework Programme. (author)

  19. Experiments on laser driven beatwave acceleration in a ponderomotively formed plasma channel

    International Nuclear Information System (INIS)

    Tochitsky, S.Ya.; Narang, R.; Filip, C.V.; Clayton, C.E.; Marsh, K.A.; Joshi, C.; Musumeci, P.; Yoder, R.B.; Rosenzweig, J.B.; Pellegrini, C.

    2004-01-01

    A 10 ps long beam of 12 MeV electrons is externally injected into a ∼3-cm long plasma beatwave excited in a laser ionized hydrogen gas. The electrons have been accelerated to 50 MeV with a gradient of ∼1.3 GeV/m. It is shown that when the effective plasma wave amplitude-length product is limited by ionization-induced defocusing (IID), acceleration of electrons is significantly enhanced by using a laser pulse with a duration longer than the time required for ions to move across the laser spot size. Both experiments and two-dimensional simulations reveal that, in this case, self-guiding of the laser pulse in a ponderomotively formed plasma channel occurs. This compensates for IID and drives the beatwave over the longer length compared to when such a channel is not present

  20. Free recall test experience potentiates strategy-driven effects of value on memory.

    Science.gov (United States)

    Cohen, Michael S; Rissman, Jesse; Hovhannisyan, Mariam; Castel, Alan D; Knowlton, Barbara J

    2017-10-01

    People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in memory via dopaminergic projections from midbrain to hippocampus (Shohamy & Adcock, 2010). We hypothesized that the latter mechanism would primarily enhance recollection-based memory, while the former mechanism would strengthen both recollection and familiarity. We also hypothesized that providing interspersed tests during study is a key to encouraging selective engagement of strategies. To test these hypotheses, we presented participants with sets of words, and each word was associated with a high or low point value. In some experiments, free recall tests were given after each list. In all experiments, a recognition test was administered 5 minutes after the final word list. Process dissociation was accomplished via remember/know judgments at recognition, a recall test probing both item memory and memory for a contextual detail (word plurality), and a task dissociation combining a recognition test for plurality (intended to probe recollection) with a speeded item recognition test (to probe familiarity). When recall tests were administered after study lists, high value strengthened both recollection and familiarity. When memory was not tested after each study list, but rather only at the end, value increased recollection but not familiarity. These dual process dissociations suggest that interspersed recall tests guide learners' use of metacognitive control to selectively apply effective encoding strategies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  1. Computational modeling of direct-drive fusion pellets and KrF-driven foil experiments

    International Nuclear Information System (INIS)

    Gardner, J.H.; Schmitt, A.J.; Dahlburg, J.P.; Pawley, C.J.; Bodner, S.E.; Obenschain, S.P.; Serlin, V.; Aglitskiy, Y.

    1998-01-01

    FAST is a radiation transport hydrodynamics code that simulates laser matter interactions of relevance to direct-drive laser fusion target design. FAST solves the Euler equations of compressible flow using the Flux-Corrected Transport finite volume method. The advection algorithm provides accurate computation of flows from nearly incompressible vortical flows to those that are highly compressible and dominated by strong pressure and density gradients. In this paper we describe the numerical techniques and physics packages. FAST has also been benchmarked with Nike laser facility experiments in which linearly perturbed, low adiabat planar plastic targets are ablatively accelerated to velocities approaching 10 7 cm/s. Over a range of perturbation wavelengths, the code results agree with the measured Rayleigh endash Taylor growth from the linear through the deeply nonlinear regimes. FAST has been applied to the two-dimensional spherical simulation design to provide surface finish and laser bandwidth tolerances for a promising new direct-drive pellet that uses a foam ablator

  2. Optimized beryllium target design for indirectly driven inertial confinement fusion experiments on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Simakov, Andrei N., E-mail: simakov@lanl.gov; Wilson, Douglas C.; Yi, Sunghwan A.; Kline, John L.; Batha, Steven H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, Daniel S.; Milovich, Jose L.; Salmonson, Jay D. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

    2014-02-15

    For indirect drive inertial confinement fusion, Beryllium (Be) ablators offer a number of important advantages as compared with other ablator materials, e.g., plastic and high density carbon. In particular, the low opacity and relatively high density of Be lead to higher rocket efficiencies giving a higher fuel implosion velocity for a given X-ray drive; and to higher ablation velocities providing more ablative stabilization and reducing the effect of hydrodynamic instabilities on the implosion performance. Be ablator advantages provide a larger target design optimization space and can significantly improve the National Ignition Facility (NIF) [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] ignition margin. Herein, we summarize the Be advantages, briefly review NIF Be target history, and present a modern, optimized, low adiabat, Revision 6 NIF Be target design. This design takes advantage of knowledge gained from recent NIF experiments, including more realistic levels of laser-plasma energy backscatter, degraded hohlraum-capsule coupling, and the presence of cross-beam energy transfer.

  3. Innovation and knowledge transference in a cluster user-driven innovation perspective – the Inovcluster experience

    Directory of Open Access Journals (Sweden)

    Teresa Paiva

    2016-04-01

    Full Text Available Our purpose with this article is to show the importance of assessing trends and promoting innovation in a real business context, through a cluster ecosystem, mainly composed of micro-enterprises in the agro-industrial Portuguese sector.As many studies show, Inovcluster (which has 158 associates, from which 120 are enterprises is also a geographic region cluster, which improves innovation performance of businesses seeking to gain competitiveness and ability to improve their exportations in the agro-industrial Portuguese sector.The role of the cluster is fundamental to creating a model for knowledge transfer of innovation capacity, interconnecting its institutional, scientific and business associates. This model has to be adapted to the sector and enterprise characteristics, relying in an interconnecting structure which is more or less decentralized according to the mentioned features. Here we present an experience and case study of the Inovcluster ecosystem and its trends and innovation transfer to business value creation, contextualized within the regional strategy for smart specialization.We have shown how, through the establishment of an Inovcluster network, it is possible to integrate the contribution of different research and academic centres, channelled to assist micro-enterprises by innovating within a geographical constraint.

  4. Monitoring stress among internal medicine residents: an experience-driven, practical and short measure.

    Science.gov (United States)

    Myszkowski, Nils; Villoing, Barbara; Zenasni, Franck; Jaury, Philippe; Boujut, Emilie

    2017-07-01

    Residents experience severely high levels of stress, depression and burnout, leading to perceived medical errors, as well as to symptoms of impairment, such as chronic anger, cognitive impairment, suicidal behavior and substance abuse. Because research has not yet provided a psychometrically robust population-specific tool to measure the level of stress of medicine residents, we aimed at building and validating such a measure. Using an inductive scale development approach, a short, pragmatic measure was built, based on the interviews of 17 medicine residents. The Internal Medicine Residency Stress Scale (IMRSS) was then administered in a sample of 259 internal medicine residents (199 females, 60 males, M Age  = 25.6) along with the Hospital Anxiety and Depression Scale, Maslach Burnout Inventory, Satisfaction With Life Scale and Ways of Coping Checklist. The IMRSS showed satisfactory internal reliability (Cronbach's α = .86), adequate structural validity - studied through Confirmatory Factor Analysis (χ 2 /df = 2.51, CFI = .94; SRMR = .037, RMSEA = .076) - and good criterion validity - the IMRSS was notably strongly correlated with emotional exhaustion (r = .64; p is recommended to quickly and frequently assess and monitor stress among internal medicine residents.

  5. Initial experience using a robotic-driven laparoscopic needle holder with ergonomic handle: assessment of surgeons' task performance and ergonomics.

    Science.gov (United States)

    Sánchez-Margallo, Juan A; Sánchez-Margallo, Francisco M

    2017-12-01

    The objective of this study is to assess the surgeons' performance and ergonomics during the use of a robotic-driven needle holder in laparoscopic suturing tasks. Six right-handed laparoscopic surgeons with different levels of experience took part in this study. Participants performed a set of three different intracorporeal suturing tasks organized in ten trials during a period of five weeks. Surgeons used both conventional (Conv) and robotic (Rob) laparoscopic needle holders. Precision using the surgical needle, quality of the intracorporeal suturing performance, execution time and leakage pressure for the urethrovesical anastomosis, as well as the ergonomics of the surgeon's hand posture, were analyzed during the first, fifth and last trials. No statistically significant differences in precision and quality of suturing performance were obtained between both groups of instruments. Surgeons required more time using the robotic instrument than using the conventional needle holder to perform the urethrovesical anastomosis, but execution time was significantly reduced after training ([Formula: see text] 0.05). There were no differences in leakage pressure for the anastomoses carried out by both instruments. After training, novice surgeons significantly improved the ergonomics of the wrist ([Formula: see text] 0.05) and index finger (Conv: 36.381[Formula: see text], Rob: 30.389[Formula: see text]; p = 0.024) when using the robotic instrument compared to the conventional needle holder. Results have shown that, although both instruments offer similar technical performance, the robotic-driven instrument results in better ergonomics for the surgeon's hand posture compared to the use of a conventional laparoscopic needle holder in intracorporeal suturing.

  6. The lived experience of rescuing people who have driven into floodwater: Understanding challenges and identifying areas for providing support.

    Science.gov (United States)

    Keech, Jacob J; Smith, Stephanie R; Peden, Amy E; Hagger, Martin S; Hamilton, Kyra

    2018-06-11

    Drowning is a major public health issue, with risk increasing during times of flood. Driving though floodwater is a major risk factor for flood-related drowning and injury, and despite widespread public health campaigns, many people continue to undertake this risky behaviour and require rescue. We aimed to identify key challenges faced by emergency services personnel when rescuing those who have driven into floodwater, and to identify strategies for supporting rescuers in this important role. Australian flood rescue operators (N=8) who had previously rescued a driver who had driven through floodwater, participated in semi-structured interviews. Data were analysed using thematic analysis. Four challenges emerged from their experiences: Involvement of untrained personnel, varying information provided by emergency telephone operators, behaviour of drivers complicating the rescue, people sightseeing floods or flood rescues, or ignoring closed roads providing sources of distraction and frustration. We propose five strategies for translating these results into practice, including: training and protocol development for (1) emergency personnel and (2) telephone operators, (3) training for rescuers regarding non-compliant rescuees, (4) educating the public, and (5) increasing compliance with closed roads. Current findings provide valuable insights into how rescuers can be supported in performing their roles, and implementation of these strategies has the potential to reduce fatalities occurring due to driving through floodwater. SO WHAT?: The strategies presented have the potential to reduce the frequency and improve the outcomes of floodwater rescues, aiding in the prevention of injury and death. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Quantification of uncertainty in photon source spot size inference during laser-driven radiography experiments at TRIDENT

    Energy Technology Data Exchange (ETDEWEB)

    Tobias, Benjamin John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Palaniyappan, Sasikumar [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gautier, Donald Cort [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mendez, Jacob [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Burris-Mog, Trevor John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Huang, Chengkun K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Favalli, Andrea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hunter, James F. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Espy, Michelle E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Schmidt, Derek William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nelson, Ronald Owen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sefkow, Adam [Univ. of Rochester, NY (United States); Shimada, Tsutomu [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Johnson, Randall Philip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fernandez, Juan Carlos [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-24

    Images of the R2DTO resolution target were obtained during laser-driven-radiography experiments performed at the TRIDENT laser facility, and analysis of these images using the Bayesian Inference Engine (BIE) determines a most probable full-width half maximum (FWHM) spot size of 78 μm. However, significant uncertainty prevails due to variation in the measured detector blur. Propagating this uncertainty in detector blur through the forward model results in an interval of probabilistic ambiguity spanning approximately 35-195 μm when the laser energy impinges on a thick (1 mm) tantalum target. In other phases of the experiment, laser energy is deposited on a thin (~100 nm) aluminum target placed 250 μm ahead of the tantalum converter. When the energetic electron beam is generated in this manner, upstream from the bremsstrahlung converter, the inferred spot size shifts to a range of much larger values, approximately 270-600 μm FWHM. This report discusses methods applied to obtain these intervals as well as concepts necessary for interpreting the result within a context of probabilistic quantitative inference.

  8. Multiscale modeling of beryllium: quantum mechanics and laser-driven shock experiments using novel diagnostics

    International Nuclear Information System (INIS)

    Swift, D.C.; Paisley, Dennis L.; Kyrala, George A.; Hauer, Allan

    2002-01-01

    Ab initio quantum mechanics was used to construct a thermodynamically complete and rigorous equation of state for beryllium in the hexagonal and body-centred cubic structures, and to predict elastic constants as a function of compression. The equation of state agreed well with Hugoniot data and previously-published equations of state, but the temperatures were significantly different. The hexagonal/bcc phase boundary agreed reasonably well with published data, suggesting that the temperatures in our new equation of state were accurate. Shock waves were induced in single crystals and polycrystalline foils of beryllium, by direct illumination using the TRIDENT laser at Los Alamos. The velocity history at the surface of the sample was measured using a line-imaging VISAR, and transient X-ray diffraction (TXD) records were obtained with a plasma backlighter and X-ray streak cameras. The VISAR records exhibited elastic precursors, plastic waves, phase changes and spall. Dual TXD records were taken, in Bragg and Laue orientations. The Bragg lines moved in response to compression in the uniaxial direction. Because direct laser drive was used, the results had to be interpreted with the aid of radiation hydrodynamics simulations to predict the loading history for each laser pulse. In the experiments where there was evidence of polymorphism in the VISAR record, additional lines appeared in the Bragg and Laue records. The corresponding pressures were consistent with the phase boundary predicted by the quantum mechanical equation of state for beryllium. A model of the response of a single crystal of beryllium to shock loading is being developed using these new theoretical and experimental results. This model will be used in meso-scale studies of the response of the microstructure, allowing us to develop a more accurate representation of the behaviour of polycrystalline beryllium.

  9. The Africa Yoga Project: A Participant-Driven Concept Map of Kenyan Teachers' Reported Experiences.

    Science.gov (United States)

    Klein, Jessalyn E; Cook-Cottone, Catherine; Giambrone, Carla

    2015-01-01

    The Africa Yoga Project (AYP) trains and funds Kenyans to teach community yoga classes. Preliminary research with a small sample of AYP teachers suggested the program had a positive impact. This study used concept mapping to explore the experiences of a larger sample. Participants brainstormed statements about how practicing and/or teaching yoga changed them. They sorted statements into self-defined piles and rated them in terms of perceived importance. Multidimensional scaling (MDS) of sort data calculated statement coordinates wherein each statement is placed in proximity to other statements as a function of how frequently statements are sorted together by participants. These results are then and mapped in a two-dimensional space. Hierarchical cluster analysis (HCA) of these data identified clusters (i.e., concepts) among statements. Cluster average importance ratings gave the concept map depth and indicated concept importance. Bridging analysis and researchers' conceptual understanding of yoga literature facilitated HCA interpretive decisions. Of 72 AYP teachers, 52 and 48 teachers participated in brainstorming and sorting/rating activities, respectively. Teachers brainstormed 93 statements about how they had changed. The resultant MDS statement map had adequate validity (stress value = .29). HCA created a 12-cluster solution with the following concepts of perceived change: Identity as a Yoga Teacher; Prosocial Development; Existential Possibility; Genuine Positive Regard; Value and Respect for Others (highest importance); Presence, Acceptance, and Competence; Service and Trust; Non-judgment and Emotion Regulation (lowest importance); Engagement and Connection; Interpersonal Effectiveness; Psychosocial Functioning; and Physical Competence and Security. Teachers perceived the AYP as facilitating change across physical, mental, and spiritual domains. Additional research is needed to quantify and compare this change to other health promotion program outcomes.

  10. Proposals on the organization of a fuel cycle of the cascade sub-critical molten salt reactor (CSMSR)

    International Nuclear Information System (INIS)

    Bychkov, A.V.; Kormilitsyn, M.V.; Melnik, M.I.; Babikov, L.G.; Ponomarev, L.I.

    2002-01-01

    At present the approach of burning out long-lived radioactive waste (RW) in the reactor core neutron flux is the most feasible one. Currently the way of closing nuclear fuel cycle (NFC) on the basis of the nuclear chemical concept of the cascade sub-critical molten salt reactor (CSMSR) is considered as the most promising one. It is characterised by a number of advantages. CSMSR controlled by a beam of protons or electrons is the optimal reactor for closing the NFC using non-aqueous fluoride methods of fuel reprocessing. They, in comparison with aqueous methods, are characterised by a small waste quantity and are less laborious because of the absence of severe requirements to the product purity. A high productivity of high-temperature electrochemical processes allows the implementation of the fuel recycling process as part of the CSMSR total technological cycle. It can be conducted in the 'on-line' mode in the bypass molten salt circuit that brings the transportation volume of high-activity materials to a minimum. In order to reprocess the CSMSR irradiated molten salt fuel on the basis of salt composition LiF-NaF-(BeF 2 ) an option, based on the following three main operations of the melt treatment, was proposed at SSC RF RIAR: (i) On-line argon treatment of molten salt fuel for removal of gaseous fission products (FP) and also FP that form volatile fluorides and aerosols; (ii) Organisation of the fuel-active metal (probably with a fine-dispersed plutonium alloy) interaction in the on-line mode for removal of 'noble' and 'semi-noble' FP and corrosion products such as Ni, Fe, Cr (when using Pu alloy it allows to regenerate at the same time of the burned-out plutonium component); (iii) Portion-by-portion (fuel composition partially being removed from the CSMSR molten salt circuit) pyroelectrochemical reprocessing of the molten salt composition aimed at the removal of lanthanides - FP followed by a return of actinides to the CSMSR fuel cycle. This technology will allow

  11. Sub-critical water as a green solvent for production of valuable materials from agricultural waste biomass: A review of recent work

    Directory of Open Access Journals (Sweden)

    A. Shitu

    2015-07-01

    Full Text Available Agricultural waste biomass generated from agricultural production and food processing industry are abundant, such as durian  peel, mango peel, corn straw, rice bran, corn shell, potato peel and many more. Due to low commercial value, these wastes are disposed in landfill, which if not managed properly may cause environmental problems. Currently, environmental laws and regulations pertaining to the pollution from agricultural waste streams by regulatory agencies are stringent and hence the application of toxic solvents during processing has become public concern. Recent development in valuable materials extraction from the decomposition of agricultural waste by sub-critical water treatment from the published literature was review. Physico-chemical characteristic (reaction temperature, reaction time and solid to liquid ratio of the sub-critical water affecting its yield were also reviewed. The utilization of biomass residue from agriculture, forest wood production and from food and feed processing industry may be an important alternative renewable energy supply. The paper also presents future research on sub-critical water.

  12. Measurement of air and VOC vapor fluxes during gas-driven soil remediation: bench-scale experiments.

    Science.gov (United States)

    Kim, Heonki; Kim, Taeyun; Shin, Seungyeop; Annable, Michael D

    2012-09-04

    In this laboratory study, an experimental method was developed for the quantitative analyses of gas fluxes in soil during advective air flow. One-dimensional column and two- and three-dimensional flow chamber models were used in this study. For the air flux measurement, n-octane vapor was used as a tracer, and it was introduced in the air flow entering the physical models. The tracer (n-octane) in the gas effluent from the models was captured for a finite period of time using a pack of activated carbon, which then was analyzed for the mass of n-octane. The air flux was calculated based on the mass of n-octane captured by the activated carbon and the inflow concentration. The measured air fluxes are in good agreement with the actual values for one- and two-dimensional model experiments. Using both the two- and three-dimensional models, the distribution of the air flux at the soil surface was measured. The distribution of the air flux was found to be affected by the depth of the saturated zone. The flux and flux distribution of a volatile contaminant (perchloroethene) was also measured by using the two-dimensional model. Quantitative information of both air and contaminant flux may be very beneficial for analyzing the performance of gas-driven subsurface remediation processes including soil vapor extraction and air sparging.

  13. Results from the TARC experiment: spallation neutron phenomenology in lead and neutron-driven nuclear transmutation by adiabatic resonance crossing.

    CERN Document Server

    Abánades, A; Andriamonje, Samuel A; Angelopoulos, Angelos; Apostolakis, Alcibiades J; Arnould, H; Belle, E; Bompas, C A; Brozzi, Delecurgo; Bueno, J; Buono, S; Carminati, F; Casagrande, Federico; Cennini, P; Collar, J I; Cerro, E; Del Moral, R; Díez, S; Dumps, Ludwig; Eleftheriadis, C; Embid, M; Fernández, R; Gálvez, J; García, J; Gelès, C; Giorni, A; González, E; González, O; Goulas, I; Heuer, R D; Hussonnois, M; Kadi, Y; Karaiskos, P; Kitis, G; Klapisch, Robert; Kokkas, P; Lacoste, V; Le Naour, C; Lèpez, C; Loiseaux, J M; Martínez-Val, J M; Méplan, O; Nifenecker, H; Oropesa, J; Papadopoulos, I M; Pavlopoulos, P; Pérez-Enciso, E; Pérez-Navarro, A; Perlado, M; Placci, A; Poza, M; Revol, Jean Pierre Charles; Rubbia, Carlo; Rubio, J A; Sakelliou, L; Saldaña, F; Savvidis, E; Schussler, F; Sirvent, C; Tamarit, J; Trubert, D; Tzima, A; Viano, J B; Vieira, S L; Vlachoudis, V; Zioutas, Konstantin; CERN. Geneva. SPS and LEP Division

    2000-01-01

    The results of the TARC experiment are summarized herewith, whose main purpose is to demonstrate the possibility of using Adiabatic Resonance Crossing (ARC) to destroy efficiently Long-Lived Fission Fragments (LLFFs) in accelerator-driven systems and to validate a new simulation developed in the framework of the Energy Amplifier programme. An experimental set-up was installed in a CERN PS proton beam line to study how neutrons, produced by spallation at relatively high energy (En * 1 MeV), slow down quasi adiabatically, with almost flat isolethargic energy distribution and reach the capture resonance energy of an element to be transmuted where they will have a high probability of being captured. Precision measurements of energy and space distributions of spallation neutrons (using 2.5 GeV/c and 3.5 GeV/c protons) slowing down in a 3.3 m x 3.3 m x 3 m lead volume and of neutron capture rates on LLFFs 99Tc, 129I, and several other elements were performed. An appropriate formalism and appropriate computational t...

  14. Configuring and Characterizing X-Rays for Laser-Driven Compression Experiments at the Dynamic Compression Sector

    Science.gov (United States)

    Li, Y.; Capatina, D.; D'Amico, K.; Eng, P.; Hawreliak, J.; Graber, T.; Rickerson, D.; Klug, J.; Rigg, P. A.; Gupta, Y. M.

    2017-06-01

    Coupling laser-driven compression experiments to the x-ray beam at the Dynamic Compression Sector (DCS) at the Advanced Photon Source (APS) of Argonne National Laboratory requires state-of-the-art x-ray focusing, pulse isolation, and diagnostics capabilities. The 100J UV pulsed laser system can be fired once every 20 minutes so precise alignment and focusing of the x-rays on each new sample must be fast and reproducible. Multiple Kirkpatrick-Baez (KB) mirrors are used to achieve a focal spot size as small as 50 μm at the target, while the strategic placement of scintillating screens, cameras, and detectors allows for fast diagnosis of the beam shape, intensity, and alignment of the sample to the x-ray beam. In addition, a series of x-ray choppers and shutters are used to ensure that the sample is exposed to only a single x-ray pulse ( 80ps) during the dynamic compression event and require highly precise synchronization. Details of the technical requirements, layout, and performance of these instruments will be presented. Work supported by DOE/NNSA.

  15. Nuclear explosive driven experiments

    International Nuclear Information System (INIS)

    Ragan, C.E.

    1981-01-01

    Ultrahigh pressures are generated in the vicinity of a nuclear explosion. We have developed diagnostic techniques to obtain precise high pressures equation-of-state data in this exotic but hostile environment

  16. Optimization by simulation of the coupling between a sub-critical reactor and its spallation source. Towards a pilot reactor; Optimisation par simulation du couplage entre un reacteur sous-critique et sa source de spallation. Application a un demonstrateur

    Energy Technology Data Exchange (ETDEWEB)

    Kerdraon, D

    2001-10-01

    Accelerator Driven Systems (ADS), based on a proton accelerator and a sub-critical core coupled with a spallation target, offer advantages in order to reduce the nuclear waste radiotoxicity before repository closure. Many studies carried out on the ADS should lead to the definition of an experimental plan which would federate the different works in progress. This thesis deals with the neutronic Monte Carlo simulations with the MCNPX code to optimize such a system in view of a pilot reactor building. First, we have recalled the main neutronic properties of an hybrid reactor. The concept of gas-cooled eXperimental Accelerator Driven System (XADS) chosen for our investigations comes from the preliminary studies done by the Framatome company. In order to transmute minor actinides, we have considered the time evolution of the main fuels which could be reasonably used for the demonstration phases. The neutronic parameters of the reactor, concerning minor actinide transmutation, are reported. Also, we have calculated the characteristic times and the transmutation rates in the case of {sup 99}Tc and {sup 129}I isotopes. We have identified some neutronic differences between an experimental and a power ADS according to the infinite multiplication coefficient, the shape factor and the level of flux to extend the demonstrator concept. We have proposed geometric solutions to keep the radial shape factor of a power ADS acceptable. In the last part, beyond the experimental XADS scope, we have examined the possible transition towards an uranium/thorium cycle based on Molten Salt Reactors using a power ADS in order to generate the required {sup 233}U proportion. (author)

  17. Results of 16 years' experiments at the critical facility of Valduc

    International Nuclear Information System (INIS)

    Houelle, M.; Mangin, D.; Maubert, L.

    After briefly recalling the sub-critical approach procedure, the fields of experimental studies on criticality explored at the Valduc Criticality Station since 1963 are listed. This was the year in which the ''appareillage B'' went into service as the first installation of sub-critical experiments of the Section [fr

  18. Results from the TARC experiment: spallation neutron phenomenology in lead and neutron-driven nuclear transmutation by adiabatic resonance crossing

    Science.gov (United States)

    Abánades, A.; Aleixandre, J.; Andriamonje, S.; Angelopoulos, A.; Apostolakis, A.; Arnould, H.; Belle, E.; Bompas, C. A.; Brozzi, D.; Bueno, J.; Buono, S.; Carminati, F.; Casagrande, F.; Cennini, P.; Collar, J. I.; Cerro, E.; Del Moral, R.; Díez, S.; Dumps, L.; Eleftheriadis, C.; Embid, M.; Fernández, R.; Gálvez, J.; García, J.; Gelès, C.; Giorni, A.; González, E.; González, O.; Goulas, I.; Heuer, D.; Hussonnois, M.; Kadi, Y.; Karaiskos, P.; Kitis, G.; Klapisch, R.; Kokkas, P.; Lacoste, V.; Le Naour, C.; López, C.; Loiseaux, J. M.; Martínez-Val, J. M.; Méplan, O.; Nifenecker, H.; Oropesa, J.; Papadopoulos, I.; Pavlopoulos, P.; Pérez-Enciso, E.; Pérez-Navarro, A.; Perlado, M.; Placci, A.; Poza, M.; Revol, J.-P.; Rubbia, C.; Rubio, J. A.; Sakelliou, L.; Saldaña, F.; Savvidis, E.; Schussler, F.; Sirvent, C.; Tamarit, J.; Trubert, D.; Tzima, A.; Viano, J. B.; Vieira, S.; Vlachoudis, V.; Zioutas, K.

    2002-02-01

    We summarize here the results of the TARC experiment whose main purpose is to demonstrate the possibility of using Adiabatic Resonance Crossing (ARC) to destroy efficiently Long-Lived Fission Fragments (LLFFs) in accelerator-driven systems and to validate a new simulation developed in the framework of the Energy Amplifier programme. An experimental set-up was installed in a CERN PS proton beam line to study how neutrons produced by spallation at relatively high energy ( E n⩾1 MeV) slow down quasi-adiabatically with almost flat isolethargic energy distribution and reach the capture resonance energy of an element to be transmuted where they will have a high probability of being captured. Precision measurements of energy and space distributions of spallation neutrons (using 2.5 and 3.5 GeV/ c protons) slowing down in a 3.3 m×3.3 m×3 m lead volume and of neutron capture rates on LLFFs 99Tc, 129I, and several other elements were performed. An appropriate formalism and appropriate computational tools necessary for the analysis and understanding of the data were developed and validated in detail. Our direct experimental observation of ARC demonstrates the possibility to destroy, in a parasitic mode, outside the Energy Amplifier core, large amounts of 99Tc or 129I at a rate exceeding the production rate, thereby making it practical to reduce correspondingly the existing stockpile of LLFFs. In addition, TARC opens up new possibilities for radioactive isotope production as an alternative to nuclear reactors, in particular for medical applications, as well as new possibilities for neutron research and industrial applications.

  19. The use of sub-critical water hydrolysis for the recovery of peptides and free amino acids from food processing wastes. Review of sources and main parameters.

    Science.gov (United States)

    Marcet, Ismael; Álvarez, Carlos; Paredes, Benjamín; Díaz, Mario

    2016-03-01

    Food industry processing wastes are produced in enormous amounts every year, such wastes are usually disposed with the corresponding economical cost it implies, in the best scenario they can be used for pet food or composting. However new promising technologies and tools have been developed in the last years aimed at recovering valuable compounds from this type of materials. In particular, sub-critical water hydrolysis (SWH) has been revealed as an interesting way for recovering high added-value molecules, and its applications have been broadly referred in the bibliography. Special interest has been focused on recovering protein hydrolysates in form of peptides or amino acids, from both animal and vegetable wastes, by means of SWH. These recovered biomolecules have a capital importance in fields such as biotechnology research, nutraceuticals, and above all in food industry, where such products can be applied with very different objectives. Present work reviews the current state of art of using sub-critical water hydrolysis for protein recovering from food industry wastes. Key parameters as reaction time, temperature, amino acid degradation and kinetic constants have been discussed. Besides, the characteristics of the raw material and the type of products that can be obtained depending on the substrate have been reviewed. Finally, the application of these hydrolysates based on their functional properties and antioxidant activity is described. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. IAEA coordinated research project (CRP) on 'Analytical and experimental benchmark analyses of accelerator driven systems'

    International Nuclear Information System (INIS)

    Abanades, Alberto; Aliberti, Gerardo; Gohar, Yousry; Talamo, Alberto; Bornos, Victor; Kiyavitskaya, Anna; Carta, Mario; Janczyszyn, Jerzy; Maiorino, Jose; Pyeon, Cheolho; Stanculescu, Alexander; Titarenko, Yury; Westmeier, Wolfram

    2008-01-01

    In December 2005, the International Atomic Energy Agency (IAEA) has started a Coordinated Research Project (CRP) on 'Analytical and Experimental Benchmark Analyses of Accelerator Driven Systems'. The overall objective of the CRP, performed within the framework of the Technical Working Group on Fast Reactors (TWGFR) of IAEA's Nuclear Energy Department, is to increase the capability of interested Member States in developing and applying advanced reactor technologies in the area of long-lived radioactive waste utilization and transmutation. The specific objective of the CRP is to improve the present understanding of the coupling of an external neutron source (e.g. spallation source) with a multiplicative sub-critical core. The participants are performing computational and experimental benchmark analyses using integrated calculation schemes and simulation methods. The CRP aims at integrating some of the planned experimental demonstration projects of the coupling between a sub-critical core and an external neutron source (e.g. YALINA Booster in Belarus, and Kyoto University's Critical Assembly (KUCA)). The objective of these experimental programs is to validate computational methods, obtain high energy nuclear data, characterize the performance of sub-critical assemblies driven by external sources, and to develop and improve techniques for sub-criticality monitoring. The paper summarizes preliminary results obtained to-date for some of the CRP benchmarks. (authors)

  1. Application of the potential-drop method to measurements of hydrogen-induced sub-critical crack growth in zirconium-2.5 wt% niobium

    International Nuclear Information System (INIS)

    Simpson, L.A.; Clarke, C.F.

    1977-10-01

    Adaptation of the potential-drop method of crack-following to the problem of hydrogen-induced sub-critical crack growth in Zr-2.5% Nb is described. Reasons for non-linearity in the calibration of crack extension against potential drop in compact tension specimens are discussed. It is shown that despite non-linearities, careful comparison of fractographic features with the potential-drop record can lead to a continuous plot of crack velocity against time or stress intensity factor. Procedures for correcting data through temperature and load changes are also described. The application of the technique to studies of the mechanism of hydrogen crack growth is illustrated with several examples. (author)

  2. A New Interpretation of Alpha-particle-driven Instabilities in Deuterium-Tritium Experiments on the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    R. Nazikian; G.J. Kramer; C.Z. Cheng; N.N. Gorelenkov; H.L. Berk; S.E. Sharapov

    2003-01-01

    The original description of alpha-particle-driven instabilities in the Tokamak Fusion Test Reactor (TFTR) in terms of Toroidal Alfvin Eigenmodes (TAEs) remained inconsistent with three fundamental characteristics of the observations: (i) the variation of the mode frequency with toroidal mode number, (ii) the chirping of the mode frequency for a given toroidal mode number, and (iii) the anti-ballooning density perturbation of the modes. It is now shown that these characteristics can be explained by observing that cylindrical-like modes can exist in the weak magnetic shear region of the plasma that then make a transition to TAEs as the central safety factor decreases in time

  3. Pyroclast/snow interactions and thermally driven slurry formation. Part 2: Experiments and theoretical extension to polydisperse tephra

    Science.gov (United States)

    Walder, J.S.

    2000-01-01

    Erosion of snow by pyroclastic flows and surges presumably involves mechanical scour, but there may be thermally driven phenomena involved as well. To investigate this possibility, layers of hot (up to 400??C), uniformly sized, fine- to medium-grained sand were emplaced vertically onto finely shaved ice ('snow'); thus there was no relative shear motion between sand and snow and no purely mechanical scour. In some cases large vapor bubbles, commonly more than 10 mm across, rose through the sand layer, burst at the surface, and caused complete convective overturn of the sand, which then scoured and mixed with snow and transformed into a slurry. In other cases no bubbling occurred and the sand passively melted its way downward into the snow as a wetting front moved upward into the sand. A continuum of behaviors between these two cases was observed. Vigorous bubbling and convection were generally favored by high temperature, small grain size, and small layer thickness. A physically based theory of heat- and mass transfer at the pyroclast/snow interface, developed in Part 1 of this paper, does a good job of explaining the observations as a manifestation of unstable vapor-driven fluidization. The theory, when extrapolated to the behavior of actual, poorly sorted pyroclastic flow sediments, leads to the prediction that the observed 'thermal-scour' phenomenon should also occur for many real pyroclastic flows passing over snow. 'Thermal scour' is therefore likely to be involved in the generation of lahars.

  4. Incompressible boundary-layer stability analysis of LFC experimental data for sub-critical Mach numbers. M.S. Thesis

    Science.gov (United States)

    Berry, S. A.

    1986-01-01

    An incompressible boundary-layer stability analysis of Laminar Flow Control (LFC) experimental data was completed and the results are presented. This analysis was undertaken for three reasons: to study laminar boundary-layer stability on a modern swept LFC airfoil; to calculate incompressible design limits of linear stability theory as applied to a modern airfoil at high subsonic speeds; and to verify the use of linear stability theory as a design tool. The experimental data were taken from the slotted LFC experiment recently completed in the NASA Langley 8-Foot Transonic Pressure Tunnel. Linear stability theory was applied and the results were compared with transition data to arrive at correlated n-factors. Results of the analysis showed that for the configuration and cases studied, Tollmien-Schlichting (TS) amplification was the dominating disturbance influencing transition. For these cases, incompressible linear stability theory correlated with an n-factor for TS waves of approximately 10 at transition. The n-factor method correlated rather consistently to this value despite a number of non-ideal conditions which indicates the method is useful as a design tool for advanced laminar flow airfoils.

  5. 2nd RCM of the CRP on Analytical and Experimental Benchmark Analyses of Accelerator Driven Systems (ADS) and Technical Meeting on Low Enriched Uranium (LEU) Fuel Utilization in Accelerator Driven Sub-critical Systems. Working Material

    International Nuclear Information System (INIS)

    2010-01-01

    The overall objective of the CRP is contributing to the generic R&D efforts in various fields common to innovative fast neutron system development, i.e., heavy liquid metal thermal hydraulics, dedicated transmutation fuels and associated core designs, theoretical nuclear reaction models, measurement and evaluation of nuclear data for transmutation, and development and validation of calculational methods and codes. Ultimately, the CRP’s overall objective is to make contributions towards the realization of a transmutation demonstration facility

  6. Non-Inductively Driven Tokamak Plasmas at Near-Unity Toroidal Beta in the Pegasus Toroidal Experiment

    Science.gov (United States)

    Reusch, Joshua

    2017-10-01

    A major goal of the spherical tokamak research program is accessing a state of low internal inductance li, high elongation κ, high toroidal and normalized beta (βt and βN) , and low collisionality without solenoidal current drive. A new local helicity injection (LHI) system in the lower divertor region of the ultra-low aspect ratio Pegasus ST provides non-solenoidally driven plasmas that exhibit most of these characteristics. LHI utilizes compact, edge-localized current sources (Ainj 4 cm2, Iinj 8 kA, Vinj 1.5 kV) for plasma startup and sustainment, and can sustain more than 200 kA of plasma current. Plasma growth via LHI is enhanced by a transition from a regime of high kink-like MHD activity to one of reduced MHD activity at higher frequencies and presumably shorter wavelengths. The strong edge current drive provided by LHI results in a hollow current density profile with low li. The low aspect ratio (R0 / a 1.2) of Pegasus allows ready access to high κ and MHD stable operation at very high normalized plasma currents (IN =Ip /aBT> 15). Thomson scattering measurements indicate Te 100 eV and ne 1 ×19 m-3. The impurity Ti evolution is correlated in time with high frequency magnetic fluctuations, implying substantial reconnection ion heating is driven by the applied helicity injection. Doppler spectroscopy indicates Ti >=Te and that the anomalous ion heating scales consistently with two fluid reconnection theory. Taken together, these features provide access to very high βt plasmas. Equilibrium analyses indicate βt up to 100% and βN 6.5 is achieved. At increasingly low BT, the discharge disrupts at the no-wall ideal stability limit. In these high βt discharges, a minimum |B| well forms over 50% of the plasma volume. This unique magnetic configuration may be of interest for testing predictions of stabilizing drift wave turbulence and/or improving energetic particle confinement. This work supported by US DOE Grants DE-FG02-96ER54375 and DE-SC0006928.

  7. Non-inductively driven tokamak plasmas at near-unity βt in the Pegasus toroidal experiment

    Science.gov (United States)

    Reusch, J. A.; Bodner, G. M.; Bongard, M. W.; Burke, M. G.; Fonck, R. J.; Pachicano, J. L.; Perry, J. M.; Pierren, C.; Rhodes, A. T.; Richner, N. J.; Rodriguez Sanchez, C.; Schlossberg, D. J.; Weberski, J. D.

    2018-05-01

    A major goal of the spherical tokamak (ST) research program is accessing a state of low internal inductance ℓi, high elongation κ, and high toroidal and normalized beta ( βt and βN) without solenoidal current drive. Local helicity injection (LHI) in the Pegasus ST [Garstka et al., Nucl. Fusion 46, S603 (2006)] provides non-solenoidally driven plasmas that exhibit these characteristics. LHI utilizes compact, edge-localized current sources for plasma startup and sustainment. It results in hollow current density profiles with low ℓi. The low aspect ratio ( R0/a ˜1.2 ) of Pegasus allows access to high κ and high normalized plasma currents ( IN=Ip/a BT>14 ). Magnetic reconnection during LHI provides auxiliary ion heating. Together, these features provide access to very high βt plasmas. Equilibrium analyses indicate that βt up to ˜100% is achieved. These high βt discharges disrupt at the ideal no-wall β limit at βN˜7.

  8. Flux-driven turbulence GDB simulations of the IWL Alcator C-Mod L-mode edge compared with experiment

    Science.gov (United States)

    Francisquez, Manaure; Zhu, Ben; Rogers, Barrett

    2017-10-01

    Prior to predicting confinement regime transitions in tokamaks one may need an accurate description of L-mode profiles and turbulence properties. These features determine the heat-flux width upon which wall integrity depends, a topic of major interest for research aid to ITER. To this end our work uses the GDB model to simulate the Alcator C-Mod edge and contributes support for its use in studying critical edge phenomena in current and future tokamaks. We carried out 3D electromagnetic flux-driven two-fluid turbulence simulations of inner wall limited (IWL) C-Mod shots spanning closed and open flux surfaces. These simulations are compared with gas puff imaging (GPI) and mirror Langmuir probe (MLP) data, examining global features and statistical properties of turbulent dynamics. GDB reproduces important qualitative aspects of the C-Mod edge regarding global density and temperature profiles, within reasonable margins, and though the turbulence statistics of the simulated turbulence follow similar quantitative trends questions remain about the code's difficulty in exactly predicting quantities like the autocorrelation time A proposed breakpoint in the near SOL pressure and the posited separation between drift and ballooning dynamics it represents are examined This work was supported by DOE-SC-0010508. This research used resources of the National Energy Research Scientific Computing Center (NERSC).

  9. Operating experience feedback report: Reliability of safety-related steam turbine-driven standby pumps. Commercial power reactors, Volume 10

    International Nuclear Information System (INIS)

    Boardman, J.R.

    1994-10-01

    This report documents a detailed analysis of failure initiators, causes and design features for steam turbine assemblies (turbines with their related components, such as governors and valves) which are used as drivers for standby pumps in the auxiliary feedwater systems of US commercial pressurized water reactor plants, and in the high pressure coolant injection and reactor core isolation cooling systems of US commercial boiling water reactor plants. These standby pumps provide a redundant source of water to remove reactor core heat as specified in individual plant safety analysis reports. The period of review for this report was from January 1974 through December 1990 for licensee event reports (LERS) and January 1985 through December 1990 for Nuclear Plant Reliability Data System (NPRDS) failure data. This study confirmed the continuing validity of conclusions of earlier studies by the US Nuclear Regulatory Commission and by the US nuclear industry that the most significant factors in failures of turbine-driven standby pumps have been the failures of the turbine-drivers and their controls. Inadequate maintenance and the use of inappropriate vendor technical information were identified as significant factors which caused recurring failures

  10. Experimental subcritical facility driven by D-D/D-T neutron generator at BARC, India

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Amar, E-mail: image@barc.gov.in; Roy, Tushar; Kashyap, Yogesh; Ray, Nirmal; Shukla, Mayank; Patel, Tarun; Bajpai, Shefali; Sarkar, P.S.; Bishnoi, Saroj

    2015-05-01

    Highlights: •Experimental subcritical facility BRAHMMA coupled to D-D/D-T neutron generator. •Preliminary results of PNS experiments reported. •Feynman-alpha noise measurements explored with continuous source. -- Abstract: The paper presents design of an experimental subcritical assembly driven by D-D/D-T neutron and preliminary experimental measurements. The system has been developed for investigating the static and dynamic neutronic properties of accelerator driven sub-critical systems. This system is modular in design and it is first in the series of subcritical assemblies being designed. The subcritical core consists of natural uranium fuel with high density polyethylene as moderator and beryllium oxide as reflector. The fuel is embedded in high density polyethylene moderator matrix. Estimated k{sub eff} of the system is ∼0.89. One of the unique features of subcritical core is the use of Beryllium oxide (BeO) as reflector and HDPE as moderator making the assembly a compact modular system. The subcritical core is coupled to Purnima Neutron Generator which works in D-D and D-T mode with both DC and pulsed operation. It has facility for online source strength monitoring using neutron tagging and programmable source modulation. Preliminary experiments have been carried out for spatial flux measurement and reactivity estimation using pulsed neutron source (PNS) techniques with D-D neutrons. Further experiments are being planned to measure the reactivity and other kinetic parameters using noise methods. This facility would also be used for carrying out studies on effect of source importance and measurement of source multiplication factor k{sub s} and external neutron source efficiency φ{sup ∗} in great details. Experiments with D-T neutrons are also underway.

  11. IAEA coordinated research project (CRP) on 'Analytical and experimental benchmark analyses of accelerator driven systems'

    Energy Technology Data Exchange (ETDEWEB)

    Abanades, Alberto [Universidad Politecnica de Madrid (Spain); Aliberti, Gerardo; Gohar, Yousry; Talamo, Alberto [ANL, Argonne (United States); Bornos, Victor; Kiyavitskaya, Anna [Joint Institute of Power Eng. and Nucl. Research ' Sosny' , Minsk (Belarus); Carta, Mario [ENEA, Casaccia (Italy); Janczyszyn, Jerzy [AGH-University of Science and Technology, Krakow (Poland); Maiorino, Jose [IPEN, Sao Paulo (Brazil); Pyeon, Cheolho [Kyoto University (Japan); Stanculescu, Alexander [IAEA, Vienna (Austria); Titarenko, Yury [ITEP, Moscow (Russian Federation); Westmeier, Wolfram [Wolfram Westmeier GmbH, Ebsdorfergrund (Germany)

    2008-07-01

    In December 2005, the International Atomic Energy Agency (IAEA) has started a Coordinated Research Project (CRP) on 'Analytical and Experimental Benchmark Analyses of Accelerator Driven Systems'. The overall objective of the CRP, performed within the framework of the Technical Working Group on Fast Reactors (TWGFR) of IAEA's Nuclear Energy Department, is to increase the capability of interested Member States in developing and applying advanced reactor technologies in the area of long-lived radioactive waste utilization and transmutation. The specific objective of the CRP is to improve the present understanding of the coupling of an external neutron source (e.g. spallation source) with a multiplicative sub-critical core. The participants are performing computational and experimental benchmark analyses using integrated calculation schemes and simulation methods. The CRP aims at integrating some of the planned experimental demonstration projects of the coupling between a sub-critical core and an external neutron source (e.g. YALINA Booster in Belarus, and Kyoto University's Critical Assembly (KUCA)). The objective of these experimental programs is to validate computational methods, obtain high energy nuclear data, characterize the performance of sub-critical assemblies driven by external sources, and to develop and improve techniques for sub-criticality monitoring. The paper summarizes preliminary results obtained to-date for some of the CRP benchmarks. (authors)

  12. Fast accelerator driven subcritical system for energy production: nuclear fuel evolution

    International Nuclear Information System (INIS)

    Barros, Graiciany de P.; Pereira, Claubia; Veloso, Maria A.F.; Costa, Antonella L.

    2011-01-01

    Accelerators Driven Systems (ADS) are an innovative type of nuclear system, which is useful for long-lived fission product transmutation and fuel regeneration. The ADS consist of a coupling of a sub-critical nuclear core reactor and a proton beam produced by a particle accelerator. These particles are injected into a target for the neutrons production by spallation reactions. The neutrons are then used to maintain the fission chain in the sub-critical core. The aim of this study is to investigate the nuclear fuel evolution of a lead cooled accelerator driven system used for energy production. The fuel studied is a mixture based upon "2"3"2Th and "2"3"3U. Since thorium is an abundant fertile material, there is hope for the thorium-cycle fuels for an accelerator driven sub-critical system. The target is a lead spallation target and the core is filled with a hexagonal lattice. High energy neutrons are used to reduce the negative reactivity caused by the presence of protoactinium, since this effect is most pronounced in the thermal range of the neutron spectrum. For that reason, such material is not added moderator to the system. In this work is used the Monte Carlo code MCNPX 2.6.0, that presents the the depletion/ burnup capability. The k_e_f_f evolution, the neutron energy spectrum in the core and the nuclear fuel evolution using ADS source (SDEF) and kcode-mode are evaluated during the burnup. (author)

  13. Wetting layer states in low density InAs/InGaAs quantum dots from sub-critical InAs coverages

    International Nuclear Information System (INIS)

    Seravalli, L; Trevisi, G; Frigeri, P; Rossi, F; Buffagni, E; Ferrari, C

    2013-01-01

    In this work we study the properties of wetting layers in InAs/InGaAs/GaAs quantum dot (QD) structures suitable for single photon emission; the mandatory low density of QDs is obtained by an molecular beam epitaxy (MBE) approach based on the deposition of sub-critical InAs coverages followed by post-growth annealing. Such a growth regime is fundamentally different from the Stranski–Krastanow (SK) one commonly used for the deposition of QDs. By fitting x-ray diffraction (XRD) spectra, ten-steps composition profiles were derived and used as inputs of model calculations of the two-dimensional quantum energy system: model results were validated by comparison with photoluminescence spectra. A strong reduction of In molar fraction in wetting layers in comparison with SK structures was found, causing a larger wavefunction delocalization for carriers that populate the wetting layer energy levels. Moreover, by considering the limits for strain relaxation when In x Ga 1−x As capping layers are used, we grew structures with the highest possible values of x to study the modifications of the energy system. When x = 0.20 the electron–heavy hole overlap is almost halved and the carriers' probability of being in the first nanometre of the wetting layer is reduced by 60%. These results will be useful for advanced design of QD nanostructures for single photon sources. (paper)

  14. A multi-fluid PSO-based algorithm for the search of the best performance of sub-critical Organic Rankine Cycles

    International Nuclear Information System (INIS)

    Cavazzini, G.; Bari, S.; Pavesi, G.; Ardizzon, G.

    2017-01-01

    The present paper focuses on the thermodynamic optimization of a sub-critical ORC for heat source temperatures in the range between 80 and 150 °C. The most significant novelty of the optimization procedure is that the optimization algorithm was modified for this particular application in order to allow the swarm particles to dynamically choose the working fluid among a list of 37 candidates during their heuristic movement, by continuously and dynamically modifying the search domain of each particle iteration-by-iteration due to the different vapour saturation lines of the chosen working fluid. The significant amount of data obtained by the optimization procedure highlighted the dependency of the system efficiency on two main parameters: the Jakob number related to the optimized cycle (Ja_o_p_t) and the ratio between the critical temperature of the working fluid and the inlet heat source temperature. At closer inspection, a third new parameter Ω was identified, resulting from the combination of the previous two, whose minimization is correlated to the maximization of system efficiency. A procedure for the preliminary estimation of the optimal cycle allowing to estimate with good accuracy the Jakob number Ja_o_p_t and the corresponding value of Ω was also developed. - Highlights: • An PSO algorithm allowing for the dynamic choice of the working fluid is presented. • Thermodynamic optimizations for several heat source temperatures were carried out. • An effective parameter for choosing the best performing working fluids is presented.

  15. Development and Validation of NODAL-LAMBDA Program for the Calculation of the Sub-criticality of LAMDA MODES By Nodal Methods in BWR reactors

    International Nuclear Information System (INIS)

    Munoz-Cobo, J. L.; Merino, R.; Escriva, A.; Melara, J.; Concejal, A.

    2014-01-01

    We have developed a 3D code with two energy groups and diffusion theory that is capable of calculating eigenvalues lambda of a BWR reactor using nodal methods and boundary conditions that calculates ALBEDO NODAL-LAMBDA from the properties of the reflector code itself. The code calculates the sub-criticality of the first harmonic, which is involved in the stability against oscillations reactor out of phase, and which is needed for calculating the decay rate for data out of phase oscillations. The code is very fast and in a few seconds is able to make a calculation of the first eigenvalues and eigenvectors, discretized solving the problem with different matrix elements zero. The code uses the LAPACK and ARPACK libraries. It was necessary to modify the LAPACK library to perform various operations with five non-diagonal matrices simultaneously in order to reduce the number of calls to bookstores and simplify the procedure for calculating the matrices in compressed format CSR. The code is validated by comparing it with the results for SIMULATE different cases and making 3D BENCHMAR of the IAEA. (Author)

  16. Toward the Replacement of Animal Experiments through the Bioinformatics-driven Analysis of 'Omics' Data from Human Cell Cultures.

    Science.gov (United States)

    Grafström, Roland C; Nymark, Penny; Hongisto, Vesa; Spjuth, Ola; Ceder, Rebecca; Willighagen, Egon; Hardy, Barry; Kaski, Samuel; Kohonen, Pekka

    2015-11-01

    This paper outlines the work for which Roland Grafström and Pekka Kohonen were awarded the 2014 Lush Science Prize. The research activities of the Grafström laboratory have, for many years, covered cancer biology studies, as well as the development and application of toxicity-predictive in vitro models to determine chemical safety. Through the integration of in silico analyses of diverse types of genomics data (transcriptomic and proteomic), their efforts have proved to fit well into the recently-developed Adverse Outcome Pathway paradigm. Genomics analysis within state-of-the-art cancer biology research and Toxicology in the 21st Century concepts share many technological tools. A key category within the Three Rs paradigm is the Replacement of animals in toxicity testing with alternative methods, such as bioinformatics-driven analyses of data obtained from human cell cultures exposed to diverse toxicants. This work was recently expanded within the pan-European SEURAT-1 project (Safety Evaluation Ultimately Replacing Animal Testing), to replace repeat-dose toxicity testing with data-rich analyses of sophisticated cell culture models. The aims and objectives of the SEURAT project have been to guide the application, analysis, interpretation and storage of 'omics' technology-derived data within the service-oriented sub-project, ToxBank. Particularly addressing the Lush Science Prize focus on the relevance of toxicity pathways, a 'data warehouse' that is under continuous expansion, coupled with the development of novel data storage and management methods for toxicology, serve to address data integration across multiple 'omics' technologies. The prize winners' guiding principles and concepts for modern knowledge management of toxicological data are summarised. The translation of basic discovery results ranged from chemical-testing and material-testing data, to information relevant to human health and environmental safety. 2015 FRAME.

  17. How older citizens engage in their health promotion: a qualitative research-driven taxonomy of experiences and meanings

    Science.gov (United States)

    Menichetti, Julia; Graffigna, Guendalina

    2016-01-01

    Objectives In this qualitative study, we provide an in-depth exploration of older people's experiences and subjective meanings concerning their engagement in health promotion as well as the emotional and pragmatic difficulties they face during their engagement. Methods The study was designed according to the ethnoscience method, which implies a participatory process that values patients' linguistic expressions to deeply understand the phenomena under the investigation and to give it a meaning. Using this method, thanks to repeated rounds of interviews and the Q-sorting task, participants created a dictionary, with the assistance of the researcher, to describe the phenomenon of interest. They agreed on a shared taxonomy of meanings and experiences related to the phenomenon. 25 North Italian older citizens participated in this study. Results Participants described a shared taxonomy of health engagement experiences by depicting 3 main positions (ie, locked position; awakening position; climbing position), which represented different experiential domains grouped by participants into 4 main semantic areas (eg, physical care, soul care, daily lifestyle, contact with ageing). Each position is characterised by specific emotions, personal representations of meaning and healthy behaviours that may sustain or hinder older citizens' engagement in health promotion. Conclusions The results of the present study suggest the importance of deeply understanding older peoples' experiences and their subjective meanings of health promotion. In particular, the results showed how their engagement in health promotion is framed in a complex system of psychological meanings, which may sustain or hinder their ability to adopt healthy behaviours. A deeper understanding of older citizens' lived experiences, their doubts and their difficulties in engaging in health promotion may offer some important cues for orienting interventions in this area. PMID:27417196

  18. How older citizens engage in their health promotion: a qualitative research-driven taxonomy of experiences and meanings.

    Science.gov (United States)

    Menichetti, Julia; Graffigna, Guendalina

    2016-07-14

    In this qualitative study, we provide an in-depth exploration of older people's experiences and subjective meanings concerning their engagement in health promotion as well as the emotional and pragmatic difficulties they face during their engagement. The study was designed according to the ethnoscience method, which implies a participatory process that values patients' linguistic expressions to deeply understand the phenomena under the investigation and to give it a meaning. Using this method, thanks to repeated rounds of interviews and the Q-sorting task, participants created a dictionary, with the assistance of the researcher, to describe the phenomenon of interest. They agreed on a shared taxonomy of meanings and experiences related to the phenomenon. 25 North Italian older citizens participated in this study. Participants described a shared taxonomy of health engagement experiences by depicting 3 main positions (ie, locked position; awakening position; climbing position), which represented different experiential domains grouped by participants into 4 main semantic areas (eg, physical care, soul care, daily lifestyle, contact with ageing). Each position is characterised by specific emotions, personal representations of meaning and healthy behaviours that may sustain or hinder older citizens' engagement in health promotion. The results of the present study suggest the importance of deeply understanding older peoples' experiences and their subjective meanings of health promotion. In particular, the results showed how their engagement in health promotion is framed in a complex system of psychological meanings, which may sustain or hinder their ability to adopt healthy behaviours. A deeper understanding of older citizens' lived experiences, their doubts and their difficulties in engaging in health promotion may offer some important cues for orienting interventions in this area. Published by the BMJ Publishing Group Limited. For permission to use (where not already

  19. Minor actinide transmutation in accelerator driven systems

    Energy Technology Data Exchange (ETDEWEB)

    Friess, Friederike [IANUS, TU Darmstadt (Germany)

    2015-07-01

    Transmutation of radioactive waste, the legacy of nuclear energy use, gains rising interest. This includes the development of facilities able to transmute minor actinides (MA) into stable or short-lived isotopes before final disposal. The most common proposal is to use a double-strata approach with accelerator-driven-systems (ADS) for the efficient transmutation of MA and power reactors to dispose plutonium. An ADS consists of a sub-critical core that reaches criticality with neutrons supplied by a spallation target. An MCNP model of the ADS system Multi Purpose Research Reactor for Hightech Applications will be presented. Depletion calculations have been performed for both standard MOX fuel and transmutation fuel with an increased content of minor actinides. The resulting transmutation rates for MAs are compared to published values. Special attention is given to selected fission products such as Tc-99 and I-129, which impact the radiation from the spent fuel significantly.

  20. Reported emergency department avoidance, use, and experiences of transgender persons in Ontario, Canada: results from a respondent-driven sampling survey.

    Science.gov (United States)

    Bauer, Greta R; Scheim, Ayden I; Deutsch, Madeline B; Massarella, Carys

    2014-06-01

    Transgender, transsexual, or transitioned (trans) people have reported avoiding medical care because of negative experiences or fear of such experiences. The extent of trans-specific negative emergency department (ED) experiences, and of ED avoidance, has not been documented. The Trans PULSE Project conducted a survey of trans people in Ontario, Canada (n=433) in 2009 to 2010, using respondent-driven sampling, a tracked network-based method for studying hidden populations. Weighted frequencies and bootstrapped 95% confidence intervals (CIs) were estimated for the trans population in Ontario and for the subgroup (n=167) reporting ED use in their felt gender. Four hundred eight participants completed the ED experience items. Trans people were young (34% aged 16 to 24 years and only 10% >55 years); approximately half were female-to-male and half male-to-female. Medically supervised hormones were used by 37% (95% CI 30% to 46%), and 27% (95% CI 20% to 35%) had at least 1 transition-related surgery. Past-year ED need was reported by 33% (95% CI 26% to 40%) of trans Ontarians, though only 71% (95% CI 40% to 91%) of those with self-reported need indicated that they were able to obtain care. An estimated 21% (95% CI 14% to 25%) reported ever avoiding ED care because of a perception that their trans status would negatively affect such an encounter. Trans-specific negative ED experiences were reported by 52% (95% CI 34% to 72%) of users presenting in their felt gender. This first exploratory analysis of ED avoidance, utilization, and experiences by trans persons documented ED avoidance and possible unmet need for emergency care among trans Ontarians. Additional research, including validation of measures, is needed. Copyright © 2013 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

  1. Measurements of beam-ion confinement during tangential beam-driven instabilities in PBX [Princeton Beta Experiment

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Kaita, R.; Takahashi, H.; Gammel, G.; Hammett, G.W.; Kaye, S.

    1987-01-01

    During tangential injection of neutral beams into low density tokamak plasmas with β > 1% in the Princeton Beta Experiment (PBX), instabilities are observed that degrade the confinement of beam ions. Neutron, charge-exchange, and diamagnetic loop measurements are examined in order to identify the mechanism or mechanisms responsible for the beam-ion transport. The data suggest a resonant interaction between the instabilities and the parallel energetic beam ions. Evidence for some nonresonant transport also exists

  2. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Heidbrink, W W; Ruskov, E; Fredrickson, E D; Gorelenkov, N; Medley, S S; Berk, H L; Harvey, R W

    2006-01-01

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at ∼2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50-100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (∼<3 MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed

  3. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Heidbrink, W W [University of California, Irvine, California (United States); Ruskov, E [University of California, Irvine, California (United States); Fredrickson, E D [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Gorelenkov, N [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Medley, S S [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Berk, H L [University of Texas, Austin, Texas (United States); Harvey, R W [CompX, Del Mar, California (United States)

    2006-09-15

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at {approx}2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50-100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10-20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power ({approx}<3 MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed.

  4. Weak effect of ion cyclotron acceleration on rapidly chirping beam-driven instabilities in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    W W,Heidbrink; E,Ruskov; E D,Fredrickson; N,Gorelenkov; S S,Medley; H L,Berk; R W,Harvey

    2006-09-01

    The fast-ion distribution function in the National Spherical Torus Experiment is modified from shot to shot while keeping the total injected power at ~2 MW. Deuterium beams of different energy and tangency radius are injected into helium L-mode plasmas, producing a rich set of instabilities, including compressional Alfven eigenmodes, toroidicity-induced Alfven eigenmodes (TAE), 50–100 kHz instabilities with rapid frequency sweeps or chirps, and strong, low frequency (10–20 kHz) fishbones. The experiment was motivated by a theory that attributes frequency chirping to the formation of holes and clumps in phase-space. In the theory, increasing the effective collision frequency of the fast ions that drive the instability can suppress frequency chirping. In the experiment, high-power (≤3MW) high harmonic fast wave (HHFW) heating accelerates the fast ions in an attempt to alter the nonlinear dynamics. Steady-frequency TAE modes diminish during the HHFW heating but there is little evidence that frequency chirping is suppressed.

  5. Design, Construction and Calibration of a Near-Infrared Four-Color Pyrometry System for Laser-Driven High Pressure Experiments

    Science.gov (United States)

    Ali, S. J.; Jeanloz, R.; Collins, G.; Spaulding, D. K.

    2010-12-01

    Current dynamic compression experiments, using both quasi-isentropic and shock-compression, allow access to pressure-temperature states both on and off the principle Hugoniot and over a wide range of conditions of direct relevance to planetary interiors. Such studies necessitate reliable temperature measurements below 4000-5000 K. Such relatively low temperature states are also of particular interest for materials such as methane and water that do not experience much heating under shock compression. In order to measure these temperatures as a function of time across the sample, a four-color, near-infrared pyrometry system is being developed for use at the Janus laser facility (LLNL) with channels at wavelengths of 932nm-1008nm, 1008nm-1108nm, 1108nm-1208nm, and 1208nm-1300nm. Each color band is fiber-coupled to an InGaAs PIN photodiode with a rise time of less than 60 ps, read using an 18 GHz oscilloscope in order to ensure time resolutions of under 200 ps. This will allow for high temporal resolution measurements of laser-driven shock compression experiments with total durations of 5-15 ns as well as correlation with simultaneous time-resolved velocity interferometry and visual-wavelength pyrometry. Calibration of the system is being accomplished using quartz targets, as the EOS for quartz is well known, along with a calibrated integrating sphere of known spectral radiance.

  6. Design and simulative experiment of an innovative trailing edge morphing mechanism driven by artificial muscles embedded in skin

    Science.gov (United States)

    Li, Hongda; Liu, Long; Xiao, Tianhang; Ang, Haisong

    2016-09-01

    In this paper, conceptual design of a tailing edge morphing mechanism developed based on a new kind of artificial muscle embedded in skin, named Driving Skin, is proposed. To demonstrate the feasibility of this conceptual design, an experiment using ordinary fishing lines to simulate the function of artificial muscles was designed and carried out. Some measures were designed to ensure measurement accuracy. The experiment result shows that the contraction ratio and force required by the morphing mechanism can be satisfied by the new artificial muscles, and a relationship between contraction ratios and morphing angles can be found. To demonstrate the practical application feasibility of this conceptual design, a wing section using ordinary ropes to simulate the function of the Driving Skin mechanism was designed and fabricated. The demonstration wing section, extremely light in weight and capable of changing thickness, performs well, with a -30^\\circ /+30^\\circ morphing angle achieved. The trailing edge morphing mechanism is efficient in re-contouring the wing profile.

  7. Teaching Experiment to Elucidate a Cation-Pi Effect in an Alkyne Cycloaddition Reaction and Illustrate Hypothesis-Driven Design of Experiments

    Science.gov (United States)

    St.Germain, Elijah J.; Horowitz, Andrew S.; Rucco, Dominic; Rezler, Evonne M.; Lepore, Salvatore D.

    2017-01-01

    An organic chemistry experiment is described that is based on recent research to elucidate a novel cation-pi interaction between tetraalkammonium cations and propargyl hydrazines. This nonbonded interaction is a key component of the mechanism of ammonium-catalyzed intramolecular cycloaddition of nitrogen to the terminal carbon of a C-C triple bond…

  8. Numerical simulation of CO2 leakage from a geologic disposal reservoir, including transitions from super- to sub-critical conditions, and boiling of liquid of CO2

    International Nuclear Information System (INIS)

    Pruess, Karsten

    2003-01-01

    The critical point of CO 2 is at temperature and pressure conditions of T crit = 31.04 C, P crit = 73.82 bar. At lower (subcritical) temperatures and/or pressures, CO 2 can exist in two different phase states, a liquid and a gaseous state, as well as in two-phase mixtures of these states. Disposal of CO 2 into brine formations would be made at supercritical pressures. However, CO 2 escaping from the storage reservoir may migrate upwards towards regions with lower temperatures and pressures, where CO 2 would be in subcritical conditions. An assessment of the fate of leaking CO 2 requires a capability to model not only supercritical but also subcritical CO 2 , as well as phase changes between liquid and gaseous CO 2 in sub-critical conditions. We have developed a methodology for numerically simulating the behavior of water-CO 2 mixtures in permeable media under conditions that may include liquid, gaseous, and supercritical CO 2 . This has been applied to simulations of leakage from a deep storage reservoir in which a rising CO 2 plume undergoes transitions from supercritical to subcritical conditions. We find strong cooling effects when liquid CO 2 rises to elevations where it begins to boil and evolve a gaseous CO 2 phase. A three-phase zone forms (aqueous - liquid - gas), which over time becomes several hundred meters thick as decreasing temperatures permit liquid CO 2 to advance to shallower elevations. Fluid mobilities are reduced in the three-phase region from phase interference effects. This impedes CO 2 upflow, causes the plume to spread out laterally, and gives rise to dispersed CO 2 discharge at the land surface. Our simulation suggests that temperatures along a CO 2 leakage path may decline to levels low enough so that solid water ice and CO 2 hydrate phases may be formed

  9. Plasma-Jet-Driven Magneto-Inertial Fusion (PJMIF): Physics and Design for a Plasma Liner Formation Experiment

    Science.gov (United States)

    Hsu, Scott; Cassibry, Jason; Witherspoon, F. Douglas

    2014-10-01

    Spherically imploding plasma liners are a potential standoff compression driver for magneto-inertial fusion, which is a hybrid of and operates in an intermediate density between those of magnetic and inertial fusion. We propose to use an array of merging supersonic plasma jets to form a spherically imploding plasma liner. The jets are to be formed by pulsed coaxial guns with contoured electrodes that are placed sufficiently far from the location of target compression such that no hardware is repetitively destroyed. As such, the repetition rate can be higher (e.g., 1 Hz) and ultimately the power-plant economics can be more attractive than most other MIF approaches. During the R&D phase, a high experimental shot rate at reasonably low cost (e.g., gun plasma-liner-formation experiment, which will provide experimental data on: (i) scaling of peak liner ram pressure versus initial jet parameters, (ii) liner non-uniformity characterization and control, and (iii) control of liner profiles for eventual gain optimization.

  10. NMR data-driven structure determination using NMR-I-TASSER in the CASD-NMR experiment

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Richard [Huazhong University of Science and Technology, School of Software Engineering (China); Wang, Yan [Huazhong University of Science and Technology, School of Life Science and Technology (China); Xue, Zhidong, E-mail: zdxue@hust.edu.cn [Huazhong University of Science and Technology, School of Software Engineering (China); Zhang, Yang, E-mail: zhng@umich.edu [University of Michigan, Department of Computational Medicine and Bioinformatics (United States)

    2015-08-15

    NMR-I-TASSER, an adaption of the I-TASSER algorithm combining NMR data for protein structure determination, recently joined the second round of the CASD-NMR experiment. Unlike many molecular dynamics-based methods, NMR-I-TASSER takes a molecular replacement-like approach to the problem by first threading the target through the PDB to identify structural templates which are then used for iterative NOE assignments and fragment structure assembly refinements. The employment of multiple templates allows NMR-I-TASSER to sample different topologies while convergence to a single structure is not required. Retroactive and blind tests of the CASD-NMR targets from Rounds 1 and 2 demonstrate that even without using NOE peak lists I-TASSER can generate correct structure topology with 15 of 20 targets having a TM-score above 0.5. With the addition of NOE-based distance restraints, NMR-I-TASSER significantly improved the I-TASSER models with all models having the TM-score above 0.5. The average RMSD was reduced from 5.29 to 2.14 Å in Round 1 and 3.18 to 1.71 Å in Round 2. There is no obvious difference in the modeling results with using raw and refined peak lists, indicating robustness of the pipeline to the NOE assignment errors. Overall, despite the low-resolution modeling the current NMR-I-TASSER pipeline provides a coarse-grained structure folding approach complementary to traditional molecular dynamics simulations, which can produce fast near-native frameworks for atomic-level structural refinement.

  11. Emotion-driven level generation

    OpenAIRE

    Togelius, Julian; Yannakakis, Georgios N.

    2016-01-01

    This chapter examines the relationship between emotions and level generation. Grounded in the experience-driven procedural content generation framework we focus on levels and introduce a taxonomy of approaches for emotion-driven level generation. We then review four characteristic level generators of our earlier work that exemplify each one of the approaches introduced. We conclude the chapter with our vision on the future of emotion-driven level generation.

  12. Spatial glyphosate and AMPA redistribution on the soil surface driven by sediment transport processes - A flume experiment.

    Science.gov (United States)

    Bento, Célia P M; Commelin, Meindert C; Baartman, Jantiene E M; Yang, Xiaomei; Peters, Piet; Mol, Hans G J; Ritsema, Coen J; Geissen, Violette

    2018-03-01

    This study investigates the influence of small-scale sediment transport on glyphosate and AMPA redistribution on the soil surface and on their off-site transport during water erosion events. Both a smooth surface (T1) and a surface with "seeding lines on the contour" (T2) were tested in a rainfall simulation experiment using soil flumes (1 × 0.5 m) with a 5% slope. A dose of 178 mg m -2 of a glyphosate-based formulation (CLINIC ® ) was applied on the upper 0.2 m of the flumes. Four 15-min rainfall events (RE) with 30-min interval in between and a total rainfall intensity of 30 mm h -1 were applied. Runoff samples were collected after each RE in a collector at the flume outlet. At the end of the four REs, soil and sediment samples were collected in the application area and in four 20 cm-segments downslope of the application area. Samples were collected according to the following visually distinguished soil surface groups: light sedimentation (LS), dark sedimentation (DS), background and aggregates. Results showed that runoff, suspended sediment and associated glyphosate and AMPA off-site transport were significantly lower in T2 than in T1. Glyphosate and AMPA off-site deposition was higher for T2 than for T1, and their contents on the soil surface decreased with increasing distance from the application area for all soil surface groups and in both treatments. The LS and DS groups presented the highest glyphosate and AMPA contents, but the background group contributed the most to the downslope off-site deposition. Glyphosate and AMPA off-target particle-bound transport was 9.4% (T1) and 17.8% (T2) of the applied amount, while water-dissolved transport was 2.8% (T1) and 0.5% (T2). Particle size and organic matter influenced the mobility of glyphosate and AMPA to off-target areas. These results indicate that the pollution risk of terrestrial and aquatic environments through runoff and deposition can be considerable. Copyright © 2017 Elsevier Ltd

  13. Role of a database-driven web site in the immediate disaster response and recovery of Academic Health Center: the Katrina experience.

    Science.gov (United States)

    Fordis, Michael; Alexander, J Douglas; McKellar, Julie

    2007-08-01

    In the wake of Hurricane Katrina's landfall on August 29, 2005, and the subsequent levee failures, operations of Tulane University School of Medicine became unsustainable. As New Orleans collapsed, faculty, students, residents, and staff were scattered nationwide. In response, four Texas medical schools created an alliance to assist Tulane in temporarily relocating operations to south Texas. Resuming operations in a three- to four-week time span required developing and implementing a coordinated communication plan in the face of widespread communication infrastructure disruptions. A keystone of the strategy involved rapidly creating a "recovery Web site" to provide essential information on immediate recovery plans, mechanisms for reestablishing communications with displaced persons, housing relocation options (over 200 students, faculty, and staff were relocated using Web site resources), classes and residency training, and other issues (e.g., financial services, counseling support) vitally important to affected individuals. The database-driven Web site was launched in four days on September 11, 2005, by modifying an existing system and completing new programming. Additional functions were added during the next week, and the site operated continuously until March 2006, providing about 890,000 pages of information in over 100,000 visitor sessions. The site proved essential in disseminating announcements, reestablishing communications among the Tulane family, and supporting relocation and recovery. This experience shows the importance of information technology in collaborative efforts of academic health centers in early disaster response and recovery, reinforcing recommendations published recently by the Association of Academic Health Centers and the National Academy of Sciences.

  14. Predicting subject-driven actions and sensory experience in a virtual world with relevance vector machine regression of fMRI data.

    Science.gov (United States)

    Valente, Giancarlo; De Martino, Federico; Esposito, Fabrizio; Goebel, Rainer; Formisano, Elia

    2011-05-15

    In this work we illustrate the approach of the Maastricht Brain Imaging Center to the PBAIC 2007 competition, where participants had to predict, based on fMRI measurements of brain activity, subject driven actions and sensory experience in a virtual world. After standard pre-processing (slice scan time correction, motion correction), we generated rating predictions based on linear Relevance Vector Machine (RVM) learning from all brain voxels. Spatial and temporal filtering of the time series was optimized rating by rating. For some of the ratings (e.g. Instructions, Hits, Faces, Velocity), linear RVM regression was accurate and very consistent within and between subjects. For other ratings (e.g. Arousal, Valence) results were less satisfactory. Our approach ranked overall second. To investigate the role of different brain regions in ratings prediction we generated predictive maps, i.e. maps of the weighted contribution of each voxel to the predicted rating. These maps generally included (but were not limited to) "specialized" regions which are consistent with results from conventional neuroimaging studies and known functional neuroanatomy. In conclusion, Sparse Bayesian Learning models, such as RVM, appear to be a valuable approach to the multivariate regression of fMRI time series. The implementation of the Automatic Relevance Determination criterion is particularly suitable and provides a good generalization, despite the limited number of samples which is typically available in fMRI. Predictive maps allow disclosing multi-voxel patterns of brain activity that predict perceptual and behavioral subjective experience. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Thorium utilization in heavy water moderated Accelerator Driven Systems

    International Nuclear Information System (INIS)

    Bajpai, Anil; Degweker, S.B.; Ghosh, Biplab

    2011-01-01

    is a much more realistic option, since it gives us a good gain with heavy water as coolant and even with light water cooled heavy water moderated reactor, the gain is somewhat lower, but still acceptable. We show that the self sustaining cycle for a critical system gives rather low discharge burnup. To obtain higher burnup, the critical reactor needs an external feed of fissile material. We show that the accelerator driven sub-critical mode of operation gives acceptable burnup in a self sustaining cycle. (author)

  16. Kinematics and dynamics of salt movement driven by sub-salt normal faulting and supra-salt sediment accumulation - combined analogue experiments and analytical calculations

    Science.gov (United States)

    Warsitzka, Michael; Kukowski, Nina; Kley, Jonas

    2017-04-01

    In extensional sedimentary basins, the movement of ductile salt is mainly controlled by the vertical displacement of the salt layer, differential loading due to syn-kinematic deposition, and tectonic shearing at the top and the base of the salt layer. During basement normal faulting, salt either tends to flow downward to the basin centre driven by its own weight or it is squeezed upward due to differential loading. In analogue experiments and analytical models, we address the interplay between normal faulting of the sub-salt basement, compaction and density inversion of the supra-salt cover and the kinematic response of the ductile salt layer. The analogue experiments consist of a ductile substratum (silicone putty) beneath a denser cover layer (sand mixture). Both layers are displaced by normal faults mimicked through a downward moving block within the rigid base of the experimental apparatus and the resulting flow patterns in the ductile layer are monitored and analysed. In the computational models using an analytical approximative solution of the Navier-Stokes equation, the steady-state flow velocity in an idealized natural salt layer is calculated in order to evaluate how flow patterns observed in the analogue experiments can be translated to nature. The analytical calculations provide estimations of the prevailing direction and velocity of salt flow above a sub-salt normal fault. The results of both modelling approaches show that under most geological conditions salt moves downwards to the hanging wall side as long as vertical offset and compaction of the cover layer are small. As soon as an effective average density of the cover is exceeded, the direction of the flow velocity reverses and the viscous material is squeezed towards the elevated footwall side. The analytical models reveal that upward flow occurs even if the average density of the overburden does not exceed the density of salt. By testing various scenarios with different layer thicknesses

  17. The trade experiment: Shielding calculations for the building hosting the subcritical system

    International Nuclear Information System (INIS)

    Burn, K. W.; Carta, M.; Casalini, L.; Kadi, Y.; Monti, S.; Nava, E.; Palomba, M.; Petrovich, C.; Picardi, L.; Rubbia, C.; Troiani, F.

    2005-01-01

    The TRADE project (TRIGA Accelerator Driven Experiment), to be performed at the existing TRIGA reactor at ENEA Casaccia, has been proposed as a validation of the accelerator-driven system (ADS) concept. TRADE will be the first experiment in which the three main components of an ADS-the accelerator, spallation target and sub-critical blanket-are coupled at a power level sufficient to encounter reactivity feedback effects. As such, TRADE represents the necessary intermediate step in the development of hybrid transmutation systems, its expected outcomes being considered crucial-in terms of proof of stability of operation, dynamic behaviour and licensing issues-for the subsequent realisation of an ADS Transmutation Demonstrator. An essential role in the feasibility study of the experiment is played by radioprotection calculations. Such a system exhibits new characteristics with respect to a traditional reactor, owing to the presence of the proton accelerator. As beam losses always occur under normal operating conditions of an accelerator, shielding studies need to be performed not only around the reactor but also along the beam line from the accelerator to the spallation target. This paper illustrates a preliminary evaluation, using Monte Carlo methods, of the additional shielding to be located around the reactor structures, the beam transport line and the existing reactor building to allow access into the reactor hall and to restrict the doses outside to their legal limits. (authors)

  18. Cylindrical IEC neutron source design for driven research reactor operation

    International Nuclear Information System (INIS)

    Miley, G.H.; Ulmen, B.; Amadio, G.; Leon, H.; Hora, H.

    2009-01-01

    A resurgence in nuclear power use is now underway worldwide. However, due many university research reactors shutdown, they must rely on using subcritical assemblies which employs a cylindrical Inertial Electrostatic Confinement (IEC) device to provide a fusion neutron source. The source is inserted in a fuel element position, with its power input controlled externally at a control panel. This feature opens the way to use of the critical assembly for a number of transient experiments such as sub-critical pulsing and neutron wave propagation. That in turn adds important new insights and excitement for the student teaching laboratory. (author)

  19. Applying a Multiple Screening Program Aided by a Guideline-driven Computerized Decision Support System—A Pilot Experience in Yun-Lin, Taiwan

    Directory of Open Access Journals (Sweden)

    Jou-Wei Lin

    2007-01-01

    Conclusion: A computer-aided screening program driven by the US Preventive Services Task Force recommendations has been successfully implemented in Yun-Lin, Taiwan, and provided useful information about local epidemiology and implications for future health policy making. [J Formos Med Assoc 2007; 106(1:58-68

  20. Electrostatically Driven Nanoballoon Actuator.

    Science.gov (United States)

    Barzegar, Hamid Reza; Yan, Aiming; Coh, Sinisa; Gracia-Espino, Eduardo; Dunn, Gabriel; Wågberg, Thomas; Louie, Steven G; Cohen, Marvin L; Zettl, Alex

    2016-11-09

    We demonstrate an inflatable nanoballoon actuator based on geometrical transitions between the inflated (cylindrical) and collapsed (flattened) forms of a carbon nanotube. In situ transmission electron microscopy experiments employing a nanoelectromechanical manipulator show that a collapsed carbon nanotube can be reinflated by electrically charging the nanotube, thus realizing an electrostatically driven nanoballoon actuator. We find that the tube actuator can be reliably cycled with only modest control voltages (few volts) with no apparent wear or fatigue. A complementary theoretical analysis identifies critical parameters for nanotube nanoballoon actuation.

  1. Gate-controlled metal-insulator transition in the LaAlO{sub 3}/SrTiO{sub 3} system with sub-critical LaAlO{sub 3} thickness

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joon Sung; Lee, Seung Ran; Chang, Jung-Won; Noh, Hyunho; Baasandorj, Lkhagvasuren; Shim, Seung-Bo; Kim, Jinhee [Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of); Seung, Sang Keun; Shin, Hyun Sup; Song, Jonghyun [Department of Physics, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2012-12-15

    We studied the electrical conduction in the LaAlO{sub 3}/SrTiO{sub 3} (LAO/STO) interface electron system with a sub-critical LAO layer thickness of {proportional_to}3.5 unit cells (uc). It was found that the true dividing point between metallic and insulating behaviour without gating lies near the LAO thickness of 3.5 uc. Our marginally metallic 3.5 uc sample showed a sharp transition to insulating state at temperatures which strongly depended on the applied negative back-gate voltage. The superior gate-controllability of the sample was attributed to its sheet carrier density which was an order of magnitude lower than those of conducting LAO/STO samples with 4 uc or more of LAO layers. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Jet outflow and open field line measurements on the C-2U advanced beam-driven field-reversed configuration plasma experiment.

    Science.gov (United States)

    Sheftman, D; Gupta, D; Roche, T; Thompson, M C; Giammanco, F; Conti, F; Marsili, P; Moreno, C D

    2016-11-01

    Knowledge and control of the axial outflow of plasma particles and energy along open-magnetic-field lines are of crucial importance to the stability and longevity of the advanced beam-driven field-reversed configuration plasma. An overview of the diagnostic methods used to perform measurements on the open field line plasma on C-2U is presented, including passive Doppler impurity spectroscopy, microwave interferometry, and triple Langmuir probe measurements. Results of these measurements provide the jet ion temperature and axial velocity, electron density, and high frequency density fluctuations.

  3. A High-Power Laser-Driven Source of Sub-nanosecond Soft X-Ray Pulses for Single-Shot Radiobiology Experiments

    Czech Academy of Sciences Publication Activity Database

    Davídková, Marie; Juha, Libor; Bittner, Michal; Koptyaev, Sergey; Hájková, Věra; Krása, Josef; Pfeifer, Miroslav; Štísová, Viktorie; Bartnik, A.; Fiedorowicz, H.; Mikolajczyk, J.; Ryc, L.; Pína, L.; Horváth, M.; Babánková, Dagmar; Cihelka, Jaroslav; Civiš, Svatopluk

    2007-01-01

    Roč. 168, č. 3 (2007), s. 382-387 ISSN 0033-7587 R&D Projects: GA ČR GA202/05/2316; GA MŠk(CZ) LC528; GA MŠk 1P04LA235; GA MŠk LC510 Institutional research plan: CEZ:AV0Z10480505; CEZ:AV0Z10100523; CEZ:AV0Z20430508; CEZ:AV0Z40400503 Keywords : soft X-rays * radiation damage to DNA * laser-driven source Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.599, year: 2007

  4. Sub-critical installations for continuous evaporations of up to 200 litres/hour - description and experimental results; Installations sous-critiques d'evaporation continue jusqu'a 200 litres/heure - description et resultats experimentaux

    Energy Technology Data Exchange (ETDEWEB)

    Auchapt, P; Bouzou, G C; Sautray, R R; Jacquotte, M C [Commissariat a l' Energie Atomique, Marcoule (France). Centre de Production de Plutonium de Marcoule

    1965-07-01

    In this report are given a detailed technological description and the test results obtained with two continuous evaporation units, one of 16 l/hr, the other of 65 l/hr. These installations are sub-critical with multiplication factors (k{sub eff}) for total reflection of 0.73 and 0.77. A third evaporator of 200 litres, also sub-critical (k{sub eff} = 0.90), is given as the limiting possible case. A description is also given of simple devices without regulator for maintaining a constant level in an extra flat, separator thus making it possible to operate without supervision in perfect safety at any concentration factor. The liberal thermal characteristics and the simple operational principles constitute a sure guarantee for operation in {alpha} and {gamma} conditions. (authors) [French] Dans ce rapport, on trouvera la description technologique detaillee et les resultats obtenus au cours des essais, de deux installations d'evaporation en continu, l'une de 16 l/h, l'autre de 65 l/h. Ces installations sont sous-critiques avec des facteurs de multiplication (k{sub eff}) en reflexion totale de 0,73 et 0,77. Un troisieme evaporateur, de 200 l/h, egalement sous-critique (k{sub eff} = 0,90), est donne comme cas limite realisable. On trouvera aussi la description de dispositifs simples, sans regulateur, permettant de garder un niveau constant dans un separateur extra-plat, ce qui permet une marche sans surveillance, en toute securite, a tous les facteurs de concentration. Les caracteristiques thermiques non poussees et les principes de fonctionnement simples, sont une garantie certaine pour l'exploitation en milieu {alpha} et {gamma}. (auteurs)

  5. Test Driven Development: Performing Art

    Science.gov (United States)

    Bache, Emily

    The art of Test Driven Development (TDD) is a skill that needs to be learnt, and which needs time and practice to master. In this workshop a select number of conference participants with considerable skill and experience are invited to perform code katas [1]. The aim is for them to demonstrate excellence and the use of Test Driven Development, and result in some high quality code. This would be for the benefit of the many programmers attending the conference, who could come along and witness high quality code being written using TDD, and get a chance to ask questions and provide feedback.

  6. Progress in z-pinch driven dynamic-hohlraums for high-temperature radiation-flow and ICF experiments at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Sanford, T W L; Nash, T J; Olson, R E; Bliss, D E; Lemke, R W; Olson, C L; Ruiz, C L; Mock, R C; Bailey, J E; Chandler, G A; Cuneo, M E; Leeper, R J; Matzen, M K; Mehlhorn, T A; Slutz, S A; Stygar, W A; Peterson, D L; Chrien, R E; Watt, R G; Roderick, N F; Cooper, G W; Apruzese, J P; Sarkisov, G S; Chittenden, J P; Haines, M G

    2004-01-01

    Progress in understanding the physics of dynamic-hohlraums is reviewed for a system capable of generating 13 TW of axial radiation for high temperature (>200 eV) radiation-flow experiments and ICF capsule implosions

  7. Numerical Calculation and Experiment of Coupled Dynamics of the Differential Velocity Vane Pump Driven by the Hybrid Higher-order Fourier Non-circular Gears

    Science.gov (United States)

    Xu, Gaohuan; Chen, Jianneng; Zhao, Huacheng

    2018-06-01

    The transmission systems of the differential velocity vane pumps (DVVP) have periodic vibrations under loads. And it is not easy to find the reason. In order to optimize the performance of the pump, the authors proposed DVVP driven by the hybrid Higher-order Fourier non-circular gears and tested it. There were also similar periodic vibrations and noises under loads. Taking into account this phenomenon, the paper proposes fluid mechanics and solid mechanics simulation methodology to analyze the coupling dynamics between fluid and transmission system and reveals the reason. The results show that the pump has the reverse drive phenomenon, which is that the blades drive the non-circular gears when the suction and discharge is alternating. The reverse drive phenomenon leads the sign of the shaft torque to be changed in positive and negative way. So the transmission system produces torsional vibrations. In order to confirm the simulation results, micro strains of the input shaft of the pump impeller are measured by the Wheatstone bridge and wireless sensor technology. The relationships between strain and torque are obtained by experimental calibration, and then the true torque of input shaft is calculated indirectly. The experimental results are consistent to the simulation results. It is proven that the periodic vibrations are mainly caused by fluid solid coupling, which leads to periodic torsional vibration of the transmission system.

  8. Study of potential of nuclear waste transmutation and safety characteristics of an hybrid system: sub critical accelerator reactor; Etude du potentiel de transmutation et des caracteristiques de surete d`un systeme hybride: accelerateur reacteur sous critique

    Energy Technology Data Exchange (ETDEWEB)

    Tchistiakov, A

    1998-04-01

    The study of potential of nuclear waste transmutation for the new reactor systems - hybrid reactors - was the object of this work. Global review of different projects is presented. The basic physical parameters definitions, as neutron surplus and relative importance of external source neutrons, are introduced and explained. For these parameters, numerical values are obtained. The advantage in neutron surplus of fast system is noted. Equilibrium model and corresponding toxicities of different isotopes nd nuclear cycles are presented. Numerical analysis for equilibrium model converge validation are performed also. The study of neutron consumption by `transmutable` Long-Lived Fission Products (Tc, I and Cs) show the possibility of their incineration in dedicated fast hybrid reactors. Equilibrium model shown the influence of reprocessing losses level to cycle toxicity level. Relations between specific fuel inventories (mass normalised by power unit) for thermal and fast spectra are examined. The differences are relatively small. Finally, few hybrid reactor concepts with different objects were analysed. These studies confirm that in frameworks of certain Nuclear Energy scenarios the fast hybrid systems can reduce significantly the radio-toxicity of fuel cycle. Preliminary analyses of sub-critical reactor behaviour show big potential of this reactor type in `Transient of Power` kind of accident, even if more detailed study is necessary. (author)

  9. The Atiri Concept for Scaling up Demand-Driven Technologies: The Experience from its Application by Dairy Goat Farmers in Embu

    International Nuclear Information System (INIS)

    Kiruiru, E.M.

    2002-01-01

    Agriculture production on smallholder farms of Kenya has continued to decline despite years of agriculture research by the Kenya Agricultural Research Institute (KARI). Farmers to access agricultural technologies resulting from poor coverage mainly attributed this to a low ability by regular extension and use of inappropriate mechanisms for transferring proven technologies. The evolvement of the Agricultural Technology and Information Response Initiative (ATIRI) in KARI in 2002 was aimed at catalyzing delivery of Impact- oriented agricultural technologies to the beneficiaries at grass-root levels on a demand-driven basis. The basic hypothesis was that both the demand for technologies and their adoption would be enhanced. The Manyatta Dairy Goat-keeping Self-help Group (MDGSG) in Embu was among the initial community-based organization (CBO) facilitated within the framework of ATIRI concept to acquire various technologies aimed at improving dairy goat productivity. Following the demand for suitable forages, the scale of planting as well as skills and knowledge of forage utilization practices significantly increased after 1.5 years. In particular, fodder trees (Calliandra calothyrsus and Leucaena trichandra) and dual-purpose sweet potato recorded the highest expansion of 500 and 1300% respectively. The mean daily milk yield per head recorded in 1996 was 0.8 compared to 2.5 lt. by 2002. The relative number of goats per household in 2002 (5.7 heads) was also significantly higher than the one recorded in 1996 (1.5 heads). These changes were generally attributed to improve feeding especially from the period 2000 when the ATIRI activities started resulting in faster growth rate and improved reproductive efficiency. The major indication to adoption of technologies is the opportunity it created for farmers to increase cash income from either sale of animals or manure. The approach to involve farmers has shown tremendous potential for scaling up technology transfer since over

  10. The GENEPI-MASURCA coupling for the neutronic investigations of subcritical multiplying media in presence of an external neutron source: The MUSE experiments

    International Nuclear Information System (INIS)

    Soule, R.; Granget, G.; Chauvin, J.P.

    1999-01-01

    Full text: Accelerator Driven Systems (ADS) are being explored in France in the frame of the research program on radioactive waste management options. Besides studies aimed to clarify the motivations for ADS, a significant program has been started to validate experimentally the main physics principles of these systems. This program was initiated at CEA Cadarache in 1995, with the sponsorship of EdF and Framatome. Since 1997, the CNRS has joined the program, which is now a common CEA-CNRS- EdF-Framatome program, open to external partners, in particular the European Community in the frame of the 5th FW Program. The experimental programs allow to validate nuclear data and calculation methods used to describe the sub-critical core, in terms of reactivity, spatial flux distributions, neutron spectra and external source worth. If the source can be used in continuous and pulsed modes, static and dynamic reactivity measurements are possible. This point is of relevance, since the experimental investigation of the different techniques to monitor the sub-criticality level during the operation of an ADS is still an open question. The future MUSE program will enter a new phase in november 1999, with the installation at MASURCA of a deuteron accelerator (GENEPI accelerator), developed at the CNRS/IN2P3/ISN of Grenoble. Improved performances are expected (in terms of the quality of the neutron pulse and source intensity), and the use of both (D,D) and (D,T) reactions, will enable to explore different neutron spectra as well as source worths and their ratios to the fission neutron worths. The paper presents the GENEPI accelerator characteristics and monitoring and the experimental configurations defined for the next phase of the MUSE experiments. (author)

  11. Rehme correlation for spacer pressure drop compared to XT-ADS rod bundle simulations and water experiment

    International Nuclear Information System (INIS)

    Batta, A.; Class, A.; Litfin, K.; Wetzel, T.

    2011-01-01

    The Rehme correlation is the most common formula to estimate the pressure drop of spacers in the design phase of new bundle geometries. It is based on considerations of momentum losses and takes into account the obstruction of the flow cross section but it ignores the geometric details of the spacer design. Within the framework of accelerator driven sub-critical reactor systems (ADS), heavy-liquid-metal (HLM) cooled fuel assemblies are considered. At the KArlsruhe Liquid metal LAboratory (KALLA) of the Karlsruhe Institute of Technology a series of experiments to quantify both pressure losses and heat transfer in HLM-cooled rod bundles are performed. The present study compares simulation results obtained with the commercial CFD code Star-CCM to experiments and the Rehme correlation. It can be shown that the Rehme correlation, simulations and experiments all yield similar trends, but quantitative predictions can only be delivered by the CFD which takes into account the full geometric details of the spacer geometry. (orig.)

  12. Data Driven Economic Model Predictive Control

    Directory of Open Access Journals (Sweden)

    Masoud Kheradmandi

    2018-04-01

    Full Text Available This manuscript addresses the problem of data driven model based economic model predictive control (MPC design. To this end, first, a data-driven Lyapunov-based MPC is designed, and shown to be capable of stabilizing a system at an unstable equilibrium point. The data driven Lyapunov-based MPC utilizes a linear time invariant (LTI model cognizant of the fact that the training data, owing to the unstable nature of the equilibrium point, has to be obtained from closed-loop operation or experiments. Simulation results are first presented demonstrating closed-loop stability under the proposed data-driven Lyapunov-based MPC. The underlying data-driven model is then utilized as the basis to design an economic MPC. The economic improvements yielded by the proposed method are illustrated through simulations on a nonlinear chemical process system example.

  13. The participation of IPEN in the IAEA coordinated research projects on accelerators driven systems (ADS)

    Energy Technology Data Exchange (ETDEWEB)

    Maiorino, J.R.; Santos, A.; Carluccio, T.; Rossi, P.C.R.; Antunes, A.; Oliveira, F. de; Lee, S.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: maiorino@ipen.br

    2007-07-01

    This paper describes the participation of the IPEN in the International Atomic Energy Agency (IAEA) Coordinated Research Projects(CRP) on Analytical and Experimental Benchmark Analysis on ADS and Low Enriched Uranium Fuel Utilization in ADS. The first CRP has as specific objective to improve the present understanding of the coupling of an external neutron source [e.g. a spallation source in the case of the accelerator driven system (ADS)] with a multiplicative sub-critical core, and the second CRP, or collaborative work, the utilization of LEU in existing or planned ADS facilities. IPEN participate in both CRP through a research contract (13388), and although there are several benchmarks defined in both CRP, presently IPEN is participating in the activities related with reactor physics benchmark of the Yalina Booster facility in Belarus, in the analytical and numerical benchmarking of methods and codes for ADS kinetics, and in the ADS target calculations. Besides, since there are plans to introduce a compact neutron generator in a sub critical core of the IPEN-MB-01 facility, a benchmark of a simulation of such project has been proposed in the LEU-ADS CRP. The paper will review the CRPs with details on the activities in which IPEN is participating. (author)

  14. The participation of IPEN in the IAEA coordinated research projects on accelerators driven systems (ADS)

    International Nuclear Information System (INIS)

    Maiorino, J.R.; Santos, A.; Carluccio, T.; Rossi, P.C.R.; Antunes, A.; Oliveira, F. de; Lee, S.M.

    2007-01-01

    This paper describes the participation of the IPEN in the International Atomic Energy Agency (IAEA) Coordinated Research Projects(CRP) on Analytical and Experimental Benchmark Analysis on ADS and Low Enriched Uranium Fuel Utilization in ADS. The first CRP has as specific objective to improve the present understanding of the coupling of an external neutron source [e.g. a spallation source in the case of the accelerator driven system (ADS)] with a multiplicative sub-critical core, and the second CRP, or collaborative work, the utilization of LEU in existing or planned ADS facilities. IPEN participate in both CRP through a research contract (13388), and although there are several benchmarks defined in both CRP, presently IPEN is participating in the activities related with reactor physics benchmark of the Yalina Booster facility in Belarus, in the analytical and numerical benchmarking of methods and codes for ADS kinetics, and in the ADS target calculations. Besides, since there are plans to introduce a compact neutron generator in a sub critical core of the IPEN-MB-01 facility, a benchmark of a simulation of such project has been proposed in the LEU-ADS CRP. The paper will review the CRPs with details on the activities in which IPEN is participating. (author)

  15. Preliminary design of a gas-cooled accelerator driven system demonstrator

    International Nuclear Information System (INIS)

    Giraud, B.; Poitevin, Y.; Ritter, G.

    2001-01-01

    At the present time, nuclear power appears to be the best solution for producing a large amount of electricity from both economical and ecological viewpoints, provided that acceptable answers to the nuclear waste concern are found. In France, this is the subject of the law 91-1381 (December 30 th , 1991). The transmutation of most of the long-lived radioactive wastes is a promising solution which could play a substantial role for the safety of the fuel cycle. Sub-critical Accelerator Driven System (ADS), coupling an ion accelerator and a sub-critical reactor, seems to have a high capacity for the fission of minor actinides and transmutation of long life fission products. The practicality on an industrial scale of partitioning and transmutation through ADS for reducing the amount of long life radio-nuclides has to be evaluated. It was recognised that the most efficient way, in terms of cost and planning, to conclusively assess the potential and the feasibility of a full scale industrial programme on ADS was to design and operate an ADS Demonstrator. The main ADS DF characteristics, defined within a joint working group, and reactor design features are described and justified. Then, main issues which call for research and development support are identified. (authors)

  16. Development and validation of a critical gradient energetic particle driven Alfven eigenmode transport model for DIII-D tilted neutral beam experiments

    Science.gov (United States)

    Waltz, R. E.; Bass, E. M.; Heidbrink, W. W.; VanZeeland, M. A.

    2015-11-01

    Recent experiments with the DIII-D tilted neutral beam injection (NBI) varying the beam energetic particle (EP) source profiles have provided strong evidence that unstable Alfven eigenmodes (AE) drive stiff EP transport at a critical EP density gradient [Heidbrink et al 2013 Nucl. Fusion 53 093006]. Here the critical gradient is identified by the local AE growth rate being equal to the local ITG/TEM growth rate at the same low toroidal mode number. The growth rates are taken from the gyrokinetic code GYRO. Simulation show that the slowing down beam-like EP distribution has a slightly lower critical gradient than the Maxwellian. The ALPHA EP density transport code [Waltz and Bass 2014 Nucl. Fusion 54 104006], used to validate the model, combines the low-n stiff EP critical density gradient AE mid-core transport with the Angioni et al (2009 Nucl. Fusion 49 055013) energy independent high-n ITG/TEM density transport model controling the central core EP density profile. For the on-axis NBI heated DIII-D shot 146102, while the net loss to the edge is small, about half the birth fast ions are transported from the central core r/a  <  0.5 and the central density is about half the slowing down density. These results are in good agreement with experimental fast ion pressure profiles inferred from MSE constrained EFIT equilibria.

  17. ECO2M: A TOUGH2 Fluid Property Module for Mixtures of Water, NaCl, and CO2, Including Super- and Sub-Critical Conditions, and Phase Change Between Liquid and Gaseous CO2

    Energy Technology Data Exchange (ETDEWEB)

    Pruess, K.

    2011-04-01

    ECO2M is a fluid property module for the TOUGH2 simulator (Version 2.0) that was designed for applications to geologic storage of CO{sub 2} in saline aquifers. It includes a comprehensive description of the thermodynamics and thermophysical properties of H{sub 2}O - NaCl - CO{sub 2} mixtures, that reproduces fluid properties largely within experimental error for temperature, pressure and salinity conditions in the range of 10 C {le} T {le} 110 C, P {le} 600 bar, and salinity from zero up to full halite saturation. The fluid property correlations used in ECO2M are identical to the earlier ECO2N fluid property package, but whereas ECO2N could represent only a single CO{sub 2}-rich phase, ECO2M can describe all possible phase conditions for brine-CO{sub 2} mixtures, including transitions between super- and sub-critical conditions, and phase change between liquid and gaseous CO{sub 2}. This allows for seamless modeling of CO{sub 2} storage and leakage. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO{sub 2}-rich) phase, as well as two-and three-phase mixtures of aqueous, liquid CO{sub 2} and gaseous CO{sub 2} phases. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. TOUGH2/ECO2M is upwardly compatible with ECO2N and accepts ECO2N-style inputs. This report gives technical specifications of ECO2M and includes instructions for preparing input data. Code applications are illustrated by means of several sample problems, including problems that had been previously solved with TOUGH2/ECO2N.

  18. Shock propagation in locally driven granular systems

    Science.gov (United States)

    Joy, Jilmy P.; Pathak, Sudhir N.; Das, Dibyendu; Rajesh, R.

    2017-09-01

    We study shock propagation in a system of initially stationary hard spheres that is driven by a continuous injection of particles at the origin. The disturbance created by the injection of energy spreads radially outward through collisions between particles. Using scaling arguments, we determine the exponent characterizing the power-law growth of this disturbance in all dimensions. The scaling functions describing the various physical quantities are determined using large-scale event-driven simulations in two and three dimensions for both elastic and inelastic systems. The results are shown to describe well the data from two different experiments on granular systems that are similarly driven.

  19. Light-Driven Alignment

    CERN Document Server

    Antonyuk, Boris P

    2009-01-01

    This book deals with influencing the properties of solids by light-driven electron transport. The theoretical basis of these effects, light-driven ordering and self-organisation, as well as optical motors are presented. With light as a tool, new ways to produce materials are opened.

  20. Data-driven background predictions for a search of direct gluino pair production in the single-lepton final state using 13 TeV pp-collisions at the CMS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lobanov, Artur; Seitz, Claudia; Melzer-Pellmann, Isabell [DESY, Hamburg (Germany)

    2016-07-01

    We present a search for direct gluino-pair production in events with a single lepton using 13 TeV pp-collisions at the CMS experiment. This final state is characterised by high multiplicities of jets and b-quark jets, as well as a large scalar sum of all jet transverse momenta, and a large scalar sum of the transverse missing momentum and the lepton transverse momentum, called L{sub T}. The dominating Standard Model backgrounds in this phase-space are tt+jets and W+jets production. A data-driven method is used to estimate the background in the search regions. All backgrounds except for QCD in the (high ΔΦ(W,l)) signal regions are predicted by from the number of events in the low ΔΦ(W,l) region, with transfer factors determined also from data, while for the multi-jet events a fake-lepton enriched side-band is used. We conclude by showing predictions and final results from data corresponding to 2.1 fb{sup -1} integrated luminosity recorded with the CMS detector during the LHC Run2 in 2015.

  1. The Italian R and D and industrial program for an accelerator driven system experimental plant

    International Nuclear Information System (INIS)

    Carta, M.; Gherardi, G.; Buono, S.; Cinotti, L.

    2001-01-01

    Accelerator Driven Systems (ADS), coupling an accelerator with a target and a sub-critical reactor, could simultaneously burn minor actinides and transmute long-lived fission products, while producing a consistent amount of electrical energy. A team of Italian R and D organizations and industries has set up a network of coordinated programs addressed to study the design issues of an 80 MW th Experimental Facility. The present memo focalizes the attention on some results obtained by the R and D activities and by the ongoing industrial short term activities aiming at the preparation of the proposed preliminary design, leaving the deal to define the details of the subsequent medium term activities to the expected common program in the European context. (author)

  2. System and safety studies of accelerator driven systems for transmutation. Annual report 2007

    International Nuclear Information System (INIS)

    Arzhanov, Vasily; Fokau, Andrei; Persson, Calle; Runevall, Odd; Sandberg, Nils; Tesinsky, Milan; Wallenius, Janne; Youpeng Zhang

    2008-05-01

    Within the project 'System and safety studies of accelerator driven systems for transmutation', research on design and safety of sub-critical reactors for recycling of minor actinides is performed. During 2007, the reactor physics division at KTH has calculated safety parameters for EFIT-400 with cermet fuel, permitting to start the transient safety analysis. The accuracy of different reactivity meters applied to the YALINA facility was assessed and neutron detection studies were performed. A model to address deviations from point kinetic behaviour was developed. Studies of basic radiation damage physics included calculations of vacancy formation and activation enthalpies in bcc niobium. In order to predict the oxygen potential of inert matrix fuels, a thermo-chemical model for mixed actinide oxides was implemented in a phase equilibrium code

  3. System and safety studies of accelerator driven systems for transmutation. Annual report 2007

    Energy Technology Data Exchange (ETDEWEB)

    Arzhanov, Vasily; Fokau, Andrei; Persson, Calle; Runevall, Odd; Sandberg, Nils; Tesinsky, Milan; Wallenius, Janne; Youpeng Zhang (Div. of Reactor Physics, Royal Institute of Technology, Stockholm (Sweden))

    2008-05-15

    Within the project 'System and safety studies of accelerator driven systems for transmutation', research on design and safety of sub-critical reactors for recycling of minor actinides is performed. During 2007, the reactor physics division at KTH has calculated safety parameters for EFIT-400 with cermet fuel, permitting to start the transient safety analysis. The accuracy of different reactivity meters applied to the YALINA facility was assessed and neutron detection studies were performed. A model to address deviations from point kinetic behaviour was developed. Studies of basic radiation damage physics included calculations of vacancy formation and activation enthalpies in bcc niobium. In order to predict the oxygen potential of inert matrix fuels, a thermo-chemical model for mixed actinide oxides was implemented in a phase equilibrium code

  4. Prompt nuclear analytical techniques for material research in accelerator driven transmutation technologies: Prospects and quantitative analyses

    International Nuclear Information System (INIS)

    Vacik, J.; Hnatowicz, V.; Cervena, J.; Perina, V.; Mach, R.

    1998-01-01

    Accelerator driven transmutation technology (ADTT) is a promising way toward liquidation of spent nuclear fuel, nuclear wastes and weapon grade Pu. The ADTT facility comprises a high current (proton) accelerator supplying a sub-critical reactor assembly with spallation neutrons. The reactor part is supposed to be cooled by molten fluorides or metals which serve, at the same time, as a carrier of nuclear fuel. Assumed high working temperature (400-600 C) and high radiation load in the subcritical reactor and spallation neutron source put forward the problem of optimal choice of ADTT construction materials, especially from the point of their radiation and corrosion resistance when in contact with liquid working media. The use of prompt nuclear analytical techniques in ADTT related material research is considered and examples of preliminary analytical results obtained using neutron depth profiling method are shown for illustration. (orig.)

  5. Model Driven Engineering

    Science.gov (United States)

    Gaševic, Dragan; Djuric, Dragan; Devedžic, Vladan

    A relevant initiative from the software engineering community called Model Driven Engineering (MDE) is being developed in parallel with the Semantic Web (Mellor et al. 2003a). The MDE approach to software development suggests that one should first develop a model of the system under study, which is then transformed into the real thing (i.e., an executable software entity). The most important research initiative in this area is the Model Driven Architecture (MDA), which is Model Driven Architecture being developed under the umbrella of the Object Management Group (OMG). This chapter describes the basic concepts of this software engineering effort.

  6. Current-driven turbulence in plasmas

    International Nuclear Information System (INIS)

    Kluiver, H. de.

    1977-10-01

    Research on plasma heating in linear and toroidal systems using current-driven turbulence is reviewed. The motivation for this research is presented. Relations between parameters describing the turbulent plasma state and macroscopic observables are given. Several linear and toroidal devices used in current-driven turbulence studies are described, followed by a discussion of special diagnostic methods used. Experimental results on the measurement of electron and ion heating, anomalous plasma conductivity and associated turbulent fluctuation spectra are reviewed. Theories on current-driven turbulence are discussed and compared with experiments. It is demonstrated from the experimental results that current-driven turbulence occurs not only for extreme values of the electric field but also for an experimentally much more accessible and wide range of parameters. This forms a basis for a discussion on possible future applications in fusion-oriented plasma research

  7. Discovery Driven Growth

    DEFF Research Database (Denmark)

    Bukh, Per Nikolaj

    2009-01-01

    Anmeldelse af Discovery Driven Growh : A breakthrough process to reduce risk and seize opportunity, af Rita G. McGrath & Ian C. MacMillan, Boston: Harvard Business Press. Udgivelsesdato: 14 august......Anmeldelse af Discovery Driven Growh : A breakthrough process to reduce risk and seize opportunity, af Rita G. McGrath & Ian C. MacMillan, Boston: Harvard Business Press. Udgivelsesdato: 14 august...

  8. Macroscopic multigroup constants for accelerator driven system core calculation

    International Nuclear Information System (INIS)

    Heimlich, Adino; Santos, Rubens Souza dos

    2011-01-01

    The high-level wastes stored in facilities above ground or shallow repositories, in close connection with its nuclear power plant, can take almost 106 years before the radiotoxicity became of the order of the background. While the disposal issue is not urgent from a technical viewpoint, it is recognized that extended storage in the facilities is not acceptable since these ones cannot provide sufficient isolation in the long term and neither is it ethical to leave the waste problem to future generations. A technique to diminish this time is to transmute these long-lived elements into short-lived elements. The approach is to use an Accelerator Driven System (ADS), a sub-critical arrangement which uses a Spallation Neutron Source (SNS), after separation the minor actinides and the long-lived fission products (LLFP), to convert them to short-lived isotopes. As an advanced reactor fuel, still today, there is a few data around these type of core systems. In this paper we generate macroscopic multigroup constants for use in calculations of a typical ADS fuel, take into consideration, the ENDF/BVI data file. Four energy groups are chosen to collapse the data from ENDF/B-VI data file by PREPRO code. A typical MOX fuel cell is used to validate the methodology. The results are used to calculate one typical subcritical ADS core. (author)

  9. Pramana – Journal of Physics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    This includes computer codes for burnup studies based on transport theory and Monte Carlo methods, codes for studying the kinetics of ADS and sub-critical facilities driven by 14 MeV neutron generators for ADS experiments and development of sub-criticality measurement methods. The paper discusses the physics issues ...

  10. PNS and statistical experiments simulation in subcritical systems using Monte-Carlo method on example of Yalina-Thermal assembly

    International Nuclear Information System (INIS)

    Sadovich, S.; Burnos, V.; Kiyavitskaya, H.; Fokov, Y.; Talamo, A.

    2013-01-01

    In subcritical systems driven by an external neutron source, the experimental methods based on pulsed neutron source (PNS) and statistical techniques play an important role for reactivity measurement. Simulation of these methods is very time-consumed procedure. For simulations in Monte-Carlo programs several improvements for neutronic calculations have been made. This paper introduces a new method for simulating PNS and statistical measurements. In this method all events occurred in the detector during simulation are stored in a file using PTRAC feature in the MCNP. After that with a special code (or post-processing) PNS and statistical methods can be simulated. Additionally different shapes of neutron pulses and its lengths as well as dead time of detectors can be included into the simulation. The methods described above have been tested on the sub-critical assembly Yalina-Thermal, located in the Joint Institute for Power and Nuclear Research SOSNY in Minsk (Belarus). A good agreement between experiment and simulation was shown. (authors)

  11. Mixed signals: The effect of conflicting reward- and goal-driven biases on selective attention

    OpenAIRE

    Preciado, Daniel; Munneke, Jaap; Theeuwes, Jan

    2017-01-01

    Attentional selection depends on the interaction between exogenous (stimulus-driven), endogenous (goal-driven), and selection history (experience-driven) factors. While endogenous and exogenous biases have been widely investigated, less is known about their interplay with value-driven attention. The present study investigated the interaction between reward-history and goal-driven biases on perceptual sensitivity (d?) and response time (RT) in a modified cueing paradigm presenting two coloured...

  12. Data-driven storytelling

    CERN Document Server

    Hurter, Christophe; Diakopoulos, Nicholas ed.; Carpendale, Sheelagh

    2018-01-01

    This book is an accessible introduction to data-driven storytelling, resulting from discussions between data visualization researchers and data journalists. This book will be the first to define the topic, present compelling examples and existing resources, as well as identify challenges and new opportunities for research.

  13. Pressure Driven Poiseuille Flow

    DEFF Research Database (Denmark)

    Stotz, Ingo Leonardo; Iaffaldano, Giampiero; Davies, D. Rhodri

    2018-01-01

    The Pacific plate is thought to be driven mainly by slab pull, associated with subduction along the Aleutians–Japan, Marianas–Izu–Bonin and Tonga–Kermadec trenches. This implies that viscous flow within the sub–Pacific asthenosphere is mainly generated by overlying plate motion (i.e. Couette flow...

  14. User-driven innovation of an outpatient department

    DEFF Research Database (Denmark)

    Broberg, Ole; Edwards, Kasper

    2012-01-01

    This paper presents experiences from a user-driven innovation process of an outpatient department in a hospital. The mixing of methods from user-driven innovation and participatory design contributed to develop an innovative concept of the spatial and organizational design of an outpatient...

  15. Test and Behaviour Driven Development with Python

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    Experience has taught us that bugs are impossible to avoid when programming. Specially on continuous delivery processes where there are new versions that refactor or incorporate new modules to the project. Although, there are different tools which help us to ensure code quality by enabling developers to catch bugs while still in the development stage. In this talk, I will talk about Test-driven development(TDD) and Behaviour-Driven development (BDD) methodologies focused on web development. Also, I will present an overview of unit testing tools as Selenium or Behave, which help us to produce working software, with fewer bugs, quickly and consistently.

  16. Patient safety and technology-driven medication

    DEFF Research Database (Denmark)

    Orbæk, Janne; Gaard, Mette; Keinicke Fabricius, Pia

    2015-01-01

    ways of educating nursing students in today's medication administration. AIM: To explore nursing students' experiences and competences with the technology-driven medication administration process. METHODS: 16 pre-graduate nursing students were included in two focus group interviews which were recorded...... for the technology-driven medication process, nursing students face difficulties in identifying and adopting best practices. The impact of using technology on the frequency, type and severity of medication errors; the technologies implications on nursing professionalism and the nurses ability to secure patient...

  17. Test-driven development with Mockito

    CERN Document Server

    Acharya, Sujoy

    2013-01-01

    This book is a hands-on guide, full of practical examples to illustrate the concepts of Test Driven Development.If you are a developer who wants to develop software following Test Driven Development using Mockito and leveraging various Mockito features, this book is ideal for you. You don't need prior knowledge of TDD, Mockito, or JUnit.It is ideal for developers, who have some experience in Java application development as well as a basic knowledge of unit testing, but it covers the basic fundamentals of TDD and JUnit testing to get you acquainted with these concepts before delving into them.

  18. Dynamical critical phenomena in driven-dissipative systems.

    Science.gov (United States)

    Sieberer, L M; Huber, S D; Altman, E; Diehl, S

    2013-05-10

    We explore the nature of the Bose condensation transition in driven open quantum systems, such as exciton-polariton condensates. Using a functional renormalization group approach formulated in the Keldysh framework, we characterize the dynamical critical behavior that governs decoherence and an effective thermalization of the low frequency dynamics. We identify a critical exponent special to the driven system, showing that it defines a new dynamical universality class. Hence critical points in driven systems lie beyond the standard classification of equilibrium dynamical phase transitions. We show how the new critical exponent can be probed in experiments with driven cold atomic systems and exciton-polariton condensates.

  19. A European roadmap for developing accelerator driven systems (ADS) for nuclear waste incineration. Executive summary

    International Nuclear Information System (INIS)

    The European Technical Working Group on ADS

    2001-01-01

    In 1998 the Research Ministers of France, Italy and Spain, set up a Ministers' Advisors Group on the use of accelerator driven systems (ADS) for nuclear waste transmutation. This led to the establishing of a technical working group under the chairmanship of Prof. Carlo Rubbia to identify the critical technical issues and to prepare a 'Roadmap' for a demonstration programme to be performed within 12 years. In the following Roadmap, the technical working group (consisting of representatives from Austria, Belgium, Finland, France, Germany, Italy, Portugal, Spain, Sweden and the JRC) has identified the steps necessary to start the construction of an experimental accelerator driven system towards the end of the decade. This is considered as an essential prerequisite to assess the safe and efficient behaviour of such systems for a large-scale deployment for transmutation purposes in the first half of this century. The development and deployment of accelerator driven systems requires three steps: a comprehensive mid- and long-term R and D program, to develop the single elements and components of the system. This includes development of new fuels and fuel cycle systems; planning, design, construction and operation of an Experimental Accelerator Driven System for the demonstration of the concept; planning, design, construction and operation of a large size prototype accelerator driven systems with subsequent large-scale deployment. Following a first phase of R and D focused on the understanding of the basic principles of ADS (already partly underway), the programmes should be streamlined and focused on a practical demonstration of the key issues. These demonstrations should cover high intensity proton accelerators (beam currents in the range 1-20 mA), spallation targets of high power (of power in excess of 1 megawatt), and their effective coupling with a sub-critical core. Cost estimates are taken into account as well as the ADS activities in Japan and USA

  20. Equilibrium of current driven rotating liquid metal

    International Nuclear Information System (INIS)

    Velikhov, E.P.; Ivanov, A.A.; Zakharov, S.V.; Zakharov, V.S.; Livadny, A.O.; Serebrennikov, K.S.

    2006-01-01

    In view of great importance of magneto-rotational instability (MRI) as a fundamental mechanism for angular momentum transfer in magnetized stellar accretion disks, several research centers are involved in experimental study of MRI under laboratory conditions. The idea of the experiment is to investigate the rotation dynamics of well conducting liquid (liquid metal) between two cylinders in axial magnetic field. In this Letter, an experimental scheme with immovable cylinders and fluid rotation driven by radial current is considered. The analytical solution of a stationary flow was found taking into account the external current. Results of axially symmetric numerical simulations of current driven fluid dynamics in experimental setup geometry are presented. The analytical solution and numerical simulations show that the current driven fluid rotation in axial magnetic field provides the axially homogeneous velocity profile suitable for MRI study in classical statement

  1. Proposal of laser-driven automobile

    Science.gov (United States)

    Yabe, Takashi; Oozono, Hirokazu; Taniguchi, Kazumoto; Ohkubo, Tomomasa; Miyazaki, Sho; Uchida, Shigeaki; Baasandash, Choijil

    2004-09-01

    We propose an automobile driven by piston motion, which is driven by water-laser coupling. The automobile can load a solar-pumped fiber laser or can be driven by ground-based lasers. The vehicle is much useful for the use in other planet in which usual combustion engine cannot be used. The piston is in a closed system and then the water will not be exhausted into vacuum. In the preliminary experiment, we succeeded to drive the cylindrical piston of 0.2g (6mm in diameter) on top of water placed inside the acrylic pipe of 8 mm in inner diameter and the laser is incident from the bottom and focused onto the upper part of water by the lens (f=8mm) attached to the bottom edge.

  2. Privacy driven internet ecosystem

    OpenAIRE

    Trinh, Tuan Anh; Gyarmati, Laszlo

    2012-01-01

    The dominant business model of today's Internet is built upon advertisements; users can access Internet services while the providers show ads to them. Although significant efforts have been made to model and analyze the economic aspects of this ecosystem, the heart of the current status quo, namely privacy, has not received the attention of the research community yet. Accordingly, we propose an economic model of the privacy driven Internet ecosystem where privacy is handled as an asset that c...

  3. Water-driven micromotors.

    Science.gov (United States)

    Gao, Wei; Pei, Allen; Wang, Joseph

    2012-09-25

    We demonstrate the first example of a water-driven bubble-propelled micromotor that eliminates the requirement for the common hydrogen peroxide fuel. The new water-driven Janus micromotor is composed of a partially coated Al-Ga binary alloy microsphere prepared via microcontact mixing of aluminum microparticles and liquid gallium. The ejection of hydrogen bubbles from the exposed Al-Ga alloy hemisphere side, upon its contact with water, provides a powerful directional propulsion thrust. Such spontaneous generation of hydrogen bubbles reflects the rapid reaction between the aluminum alloy and water. The resulting water-driven spherical motors can move at remarkable speeds of 3 mm s(-1) (i.e., 150 body length s(-1)), while exerting large forces exceeding 500 pN. Factors influencing the efficiency of the aluminum-water reaction and the resulting propulsion behavior and motor lifetime, including the ionic strength and environmental pH, are investigated. The resulting water-propelled Al-Ga/Ti motors move efficiently in different biological media (e.g., human serum) and hold considerable promise for diverse biomedical or industrial applications.

  4. Functional Domain Driven Design

    OpenAIRE

    Herrera Guzmán, Sergio

    2016-01-01

    Las tecnologías están en constante expansión y evolución, diseñando nuevas técnicas para cumplir con su fin. En el desarrollo de software, las herramientas y pautas para la elaboración de productos software constituyen una pieza en constante evolución, necesarias para la toma de decisiones sobre los proyectos a realizar. Uno de los arquetipos para el desarrollo de software es el denominado Domain Driven Design, donde es importante conocer ampliamente el negocio que se desea modelar en form...

  5. Constellations-driven innovation

    DEFF Research Database (Denmark)

    Hansbøl, Mikala

    2011-01-01

    The paper presents a science and technology studies and actor-network-theory inspired approach to understanding the development and ongoing re-didactication and re-design of a Danish developed presentation tool called the Theme Board (Tematavlen.dk). It is argued that this approach provides a par...... a particularly useful point of departure for engaging in researching innovation and didactic design of digital teaching and learning instruments such as the Theme Board that are programmed and serviced 'in the sky'. I call this approach: constellation-driven innovations....

  6. Information-Driven Inspections

    International Nuclear Information System (INIS)

    Laughter, Mark D.; Whitaker, J. Michael; Lockwood, Dunbar

    2010-01-01

    New uranium enrichment capacity is being built worldwide in response to perceived shortfalls in future supply. To meet increasing safeguards responsibilities with limited resources, the nonproliferation community is exploring next-generation concepts to increase the effectiveness and efficiency of safeguards, such as advanced technologies to enable unattended monitoring of nuclear material. These include attribute measurement technologies, data authentication tools, and transmission and security methods. However, there are several conceptual issues with how such data would be used to improve the ability of a safeguards inspectorate such as the International Atomic Energy Agency (IAEA) to reach better safeguards conclusions regarding the activities of a State. The IAEA is pursuing the implementation of information-driven safeguards, whereby all available sources of information are used to make the application of safeguards more effective and efficient. Data from continuous, unattended monitoring systems can be used to optimize on-site inspection scheduling and activities at declared facilities, resulting in fewer, better inspections. Such information-driven inspections are the logical evolution of inspection planning - making use of all available information to enhance scheduled and randomized inspections. Data collection and analysis approaches for unattended monitoring systems can be designed to protect sensitive information while enabling information-driven inspections. A number of such inspections within a predetermined range could reduce inspection frequency while providing an equal or greater level of deterrence against illicit activity, all while meeting operator and technology holder requirements and reducing inspector and operator burden. Three options for using unattended monitoring data to determine an information-driven inspection schedule are to (1) send all unattended monitoring data off-site, which will require advances in data analysis techniques to

  7. Heat driven pulse pump

    Science.gov (United States)

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

    2000-01-01

    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  8. Plasma-driven liners

    International Nuclear Information System (INIS)

    Kilic, H.; Linhart, J.G.; Bortolotti, A.; Nardi, V.

    1992-01-01

    The deposition of thermal energy by laser or ion beams in an ablator is capable of producing a very large acceleration of the adjacent pusher - for power densities of 100 Terrawatts/cm 2 , ablator pressure in the range of 10 Mbar is attainable. In the case of a plasma drive such driving pressures and accelerations are not directly possible. When a snowplough (SP) is used to accelerate a thin liner, the driving pressure is that of the magnetic piston pushing the SP, i.e. at most 0.1 Mbar. However, the initial radius r 0 of the liner can be a few centimeters, instead of 1 (mm) as in the case in direct pellet implosions. In order to compete with the performance of the beam-driven liners, the plasma drive must demonstrate that a) thin liner retains a high density during the implosion (lasting a fraction of a μsec); b) radial compression ratio r 0 /r min of the order of 100 can be attained. It is also attractive to consider the staging of two or more liners in order to get sharpening and amplifications of the pressure and/or radiation pulse. If a) and b) are verified then the final pressures produced will be comparable with those of the beam-driven implosions. (author) 5 refs., 3 figs

  9. Data Driven Tuning of Inventory Controllers

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted; Santacoloma, Paloma Andrade; Poulsen, Niels Kjølstad

    2007-01-01

    A systematic method for criterion based tuning of inventory controllers based on data-driven iterative feedback tuning is presented. This tuning method circumvent problems with modeling bias. The process model used for the design of the inventory control is utilized in the tuning...... as an approximation to reduce time required on experiments. The method is illustrated in an application with a multivariable inventory control implementation on a four tank system....

  10. Dynamic signatures of driven vortex motion.

    Energy Technology Data Exchange (ETDEWEB)

    Crabtree, G. W.; Kwok, W. K.; Lopez, D.; Olsson, R. J.; Paulius, L. M.; Petrean, A. M.; Safar, H.

    1999-09-16

    We probe the dynamic nature of driven vortex motion in superconductors with a new type of transport experiment. An inhomogeneous Lorentz driving force is applied to the sample, inducing vortex velocity gradients that distinguish the hydrodynamic motion of the vortex liquid from the elastic and-plastic motion of the vortex solid. We observe elastic depinning of the vortex lattice at the critical current, and shear induced plastic slip of the lattice at high Lorentz force gradients.

  11. Non-driven micromechanical gyroscopes and their applications

    CERN Document Server

    Zhang, Fuxue; Wang, Guosheng

    2018-01-01

    This book comprehensively and systematically introduces readers to the theories, structures, performance and applications of non-driven mechanical and non-driven micromechanical gyroscopes. The book is divided into three parts, the first of which mainly addresses mathematic models, precision, performance and operating error in non-driven mechanical gyroscopes. The second part focuses on the operating theory, error, phase shift and performance experiments involving non-driven micromechanical gyroscopes in rotating flight carriers, while the third part shares insights into the application of non-driven micromechanical gyroscopes in control systems for rotating flight carriers. The book offers a unique resource for all researchers and engineers who are interested in the use of inertial devices and automatic control systems for rotating flight carriers.  It can also serve as a reference book for undergraduates, graduates and instructors in related fields at colleges and universities.

  12. Consistent model driven architecture

    Science.gov (United States)

    Niepostyn, Stanisław J.

    2015-09-01

    The goal of the MDA is to produce software systems from abstract models in a way where human interaction is restricted to a minimum. These abstract models are based on the UML language. However, the semantics of UML models is defined in a natural language. Subsequently the verification of consistency of these diagrams is needed in order to identify errors in requirements at the early stage of the development process. The verification of consistency is difficult due to a semi-formal nature of UML diagrams. We propose automatic verification of consistency of the series of UML diagrams originating from abstract models implemented with our consistency rules. This Consistent Model Driven Architecture approach enables us to generate automatically complete workflow applications from consistent and complete models developed from abstract models (e.g. Business Context Diagram). Therefore, our method can be used to check practicability (feasibility) of software architecture models.

  13. Employee-driven innovation

    DEFF Research Database (Denmark)

    Kesting, Peter; Ulhøi, John Parm

    2015-01-01

    Purpose – The purpose of this paper is to outline the “grand structure” of the phenomenon in order to identify both the underlying processes and core drivers of employee-driven innovation (EDI). Design/methodology/approach – This is a conceptual paper. It particularly applies the insights...... of contemporary research on routine and organizational decision making to the specific case of EDI. Findings – The main result of the paper is that, from a theoretical point of view, it makes perfect sense to involve ordinary employees in innovation decisions. However, it is also outlined that naıve or ungoverned...... participation is counterproductive, and that it is quite difficult to realize the hidden potential in a supportive way. Research limitations/implications – The main implication is that basic mechanisms for employee participation also apply to innovation decisions, although often in a different way. However...

  14. Temperature-Driven Convection

    Science.gov (United States)

    Bohan, Richard J.; Vandegrift, Guy

    2003-02-01

    Warm air aloft is stable. This explains the lack of strong winds in a warm front and how nighttime radiative cooling can lead to motionless air that can trap smog. The stability of stratospheric air can be attributed to the fact that it is heated from above as ultraviolet radiation strikes the ozone layer. On the other hand, fluid heated from below is unstable and can lead to Bernard convection cells. This explains the generally turbulent nature of the troposphere, which receives a significant fraction of its heat directly from the Earth's warmer surface. The instability of cold fluid aloft explains the violent nature of a cold front, as well as the motion of Earth's magma, which is driven by radioactive heating deep within the Earth's mantle. This paper describes how both effects can be demonstrated using four standard beakers, ice, and a bit of food coloring.

  15. Towards Player-Driven Procedural Content Generation

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Togelius, Julian

    2012-01-01

    Generating immersive game content is one of the ultimate goals for a game designer. This goal can be achieved by realizing the fact that players’ perception of the same game differ according to a number of factors including: players’ personality, playing styles, expertise and culture background....... While one player might find the game immersive, others may quit playing as a result of encountering a seemingly insoluble problem. One promising avenue towards optimizing the gameplay experience for individual game players is to tailor player experience in real-time via automatic game content generation......-driven content generation....

  16. Effects-Driven IT Development

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2010-01-01

    We present effects-driven IT development as an instrument for pursuing and reinforcing Participatory Design (PD) when it is applied in commercial information technology (IT) projects. Effects-driven IT development supports the management of a sustained PD process throughout design and organizatio......We present effects-driven IT development as an instrument for pursuing and reinforcing Participatory Design (PD) when it is applied in commercial information technology (IT) projects. Effects-driven IT development supports the management of a sustained PD process throughout design...

  17. Laser-driven polarized sources of hydrogen and deuterium

    International Nuclear Information System (INIS)

    Young, L.; Holt, R.J.; Green, M.C.; Kowalczyk, R.S.

    1988-01-01

    A novel laser-driven polarized source of hydrogen and deuterium which operates on the principle of spin exchange optical pumping is described. The advantages of this method over conventional polarized sources for internal target experiments are presented. Technological difficulties which prevent ideal source operation are outlined along with proposed solutions. At present, the laser-driven polarized hydrogen source delivers 8 /times/ 10 16 atoms/s with a polarization (P/sub z/) of 24%. 9 refs., 2 figs

  18. Driven Phases of Quantum Matter

    Science.gov (United States)

    Khemani, Vedika; von Keyserlingk, Curt; Lazarides, Achilleas; Moessner, Roderich; Sondhi, Shivaji

    Clean and interacting periodically driven quantum systems are believed to exhibit a single, trivial ``infinite-temperature'' Floquet-ergodic phase. By contrast, I will show that their disordered Floquet many-body localized counterparts can exhibit distinct ordered phases with spontaneously broken symmetries delineated by sharp transitions. Some of these are analogs of equilibrium states, while others are genuinely new to the Floquet setting. I will show that a subset of these novel phases are absolutely stableto all weak local deformations of the underlying Floquet drives, and spontaneously break Hamiltonian dependent emergent symmetries. Strikingly, they simultaneously also break the underlying time-translation symmetry of the Floquet drive and the order parameter exhibits oscillations at multiples of the fundamental period. This ``time-crystallinity'' goes hand in hand with spatial symmetry breaking and, altogether, these phases exhibit a novel form of simultaneous long-range order in space and time. I will describe how this spatiotemporal order can be detected in experiments involving quenches from a broad class of initial states.

  19. The Plastic Bakery : A Case of Material Driven Design

    NARCIS (Netherlands)

    Majumdar, P.; Karana, E.; Sonneveld, M.H.; Karana, E.; Giaccardi, E.; Nimkulrat, N.; Niedderer, K.; Camere, S.

    2017-01-01

    A growing number of scholars argue that understanding how people experience materials in products, i.e. Materials Experience, is essential in
    designing meaningful material applications. Material Driven Design (MDD) has been developed as the method to understand these experiential traits
    of

  20. User Driven Innovation in the Building Process

    DEFF Research Database (Denmark)

    Christiansson, Per; Sørensen, Kristian Birch; Rødtness, Mette

    2008-01-01

    During the late years there has been an ever-increasing focus on the possibilities to change the building process to raise quality on the final building products as well as the activities of actors involved in the building process. One reason for this interest is the new opportunities evolving du...... building design. A general methodological framework and meta ontology for Virtual Innovation in Construction is presented as well as findings from implementation of the method....... to introduction of advanced information and communication technology (ICT). The paper focuses on creative changes of the building process powered by user driven innovation activities. An overview of existing user driven innovation methodologies is given as well experiences from the ongoing Virtual Innovation...

  1. MYRRHA: a multipurpose accelerator driven system for research and development

    International Nuclear Information System (INIS)

    Benoit, Ph.; Ait Abderrahim, H.; Kupschus, P.; Malambu, E.; Tichelen, K. van; Arien, B.; Vermeersch, F.; Jongen, Y.; Vandeplassche, D.; Ternier, S.

    2001-01-01

    SCK-CEN, the Belgian Nuclear Research Centre, and IBA s.a., Ion Beam Application, a world leader in accelerator technology, want to fulfil a prominent role in the Accelerator Driven Systems field and are designing an ADS prototype, the MYRRHA Project, and conducting an associated R and D programme. The partners are foreseeing MYRRHA as a first step towards the European ADS-Demo facility. The project focuses primarily on ADS related research, i.e. structural materials and nuclear fuel research, liquid metals and associated aspects, sub-critical reactor physics and subsequently on applications such as waste transmutation, radioisotope production and safety research on sub-critical systems. In this respect, the MYRRHA system should become a new major research infrastructure for the European partners presently involved in the ADS Demo development, supporting and enabling the international R and D programs. Ion Beam Applications, the Belgium world leader in particle accelerators, had joined the MYRRHA Project to perform the accelerator development. Currently the study and preliminary conceptual design of the MYRRHA system is going on and an intensive R and D programme is conducted to assess the most risky points of the present design. This study will define the final choice of the characteristics of the facility depending on the selected fields of application to be achieved. The MYRRHA concept, as it is today, is based on the coupling of an upgraded commercial proton accelerator with a spallation target surrounded by a subcritical neutron-multiplying medium. Its design is determined by the versatility m applications that should be made possible. Further technical and/or strategic developments of the project might change the concept. A cyclotron, based on positive ion acceleration technology brings the protons up to an energy level of 350 MeV. The nominal current is 5 mA of protons. The spallation target system consists in a circuit with, at the upper part, a free

  2. Current driven wiggler

    Science.gov (United States)

    Tournes, C.; Aucouturier, J.; Arnaud, B.; Brasile, J. P.; Convert, G.; Simon, M.

    1992-07-01

    A current-driven wiggler is the cornerstone of an innovative, compact, high-efficiency, transportable tunable free-electron laser (FEL), the feasibility of which is currently being evaluated by Thomson-CSF. The salient advantages are: compactness of the FEL, along with the possibility to accelerate the beam through several successive passes through the accelerating section (the number of passes being defined by the final wavelength of the radiation; i.e. visible, MWIR, LWIR); the wiggler can be turned off and be transparent to the beam until the last pass. Wiggler periodicities as small as 5 mm can be achieved, hence contributing to FEL compactness. To achieve overall efficiencies in the range of 10% at visible wavelengths, not only the wiggler periodicity must be variable, but the strength of the magnetic field of each period can be adjusted separately and fine-tuned versus time during the macropulse, so as to take into account the growing contribution of the wave energy in the cavity to the total ponderomotive force. The salient theoretical point of this design is the optimization of the parameters defining each period of the wiggler for each micropacket of the macropulse. The salient technology point is the mechanical and thermal design of the wiggler which allows the required high currents to achieve magnetic fields up to 2T.

  3. Customer-driven competition

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, R. [Ontario Hydro, Toronto, ON (Canada)

    1996-12-31

    Ontario Hydro`s customer-driven strategy, recently approved by Hydro`s Executive Board, was described. The strategy is founded on the following components: (1) the dissolution of the Ontario power pool, i.e., the loss of Hydro`s franchise monopoly on generation, leaving only power transmission in the hands of the Corporation, (2) divestment of Ontario Hydro`s system operations and market operations functions to a new, independent Crown corporation called the Central Market Operator, (3) functional and organizational unbundling of Ontario Hydro into three signature businesses, Genco, Transco, and Retailco, and in the latter two, the functional unbundling of wires from sales and services, (4) a fully commercial Ontario Hydro with normal corporate powers, and (5) a corporate strategy for Ontario Hydro to grow in businesses in an open, symmetrical North American energy market. According to Ontario Hydro management this will allow competition and choice to all customers, have a disciplining effect on prices, and give rise to a retail market of new products and services, while at the same time preserve and enhance the value of public investment in the Corporation.

  4. Digitally-Driven Architecture

    Directory of Open Access Journals (Sweden)

    Henriette Bier

    2014-07-01

    Full Text Available The shift from mechanical to digital forces architects to reposition themselves: Architects generate digital information, which can be used not only in designing and fabricating building components but also in embedding behaviours into buildings. This implies that, similar to the way that industrial design and fabrication with its concepts of standardisation and serial production influenced modernist architecture, digital design and fabrication influences contemporary architecture. While standardisation focused on processes of rationalisation of form, mass-customisation as a new paradigm that replaces mass-production, addresses non-standard, complex, and flexible designs. Furthermore, knowledge about the designed object can be encoded in digital data pertaining not just to the geometry of a design but also to its physical or other behaviours within an environment. Digitally-driven architecture implies, therefore, not only digitally-designed and fabricated architecture, it also implies architecture – built form – that can be controlled, actuated, and animated by digital means.In this context, this sixth Footprint issue examines the influence of digital means as pragmatic and conceptual instruments for actuating architecture. The focus is not so much on computer-based systems for the development of architectural designs, but on architecture incorporating digital control, sens­ing, actuating, or other mechanisms that enable buildings to inter­act with their users and surroundings in real time in the real world through physical or sensory change and variation.

  5. Digitally-Driven Architecture

    Directory of Open Access Journals (Sweden)

    Henriette Bier

    2010-06-01

    Full Text Available The shift from mechanical to digital forces architects to reposition themselves: Architects generate digital information, which can be used not only in designing and fabricating building components but also in embedding behaviours into buildings. This implies that, similar to the way that industrial design and fabrication with its concepts of standardisation and serial production influenced modernist architecture, digital design and fabrication influences contemporary architecture. While standardisa­tion focused on processes of rationalisation of form, mass-customisation as a new paradigm that replaces mass-production, addresses non-standard, complex, and flexible designs. Furthermore, knowledge about the designed object can be encoded in digital data pertaining not just to the geometry of a design but also to its physical or other behaviours within an environment. Digitally-driven architecture implies, therefore, not only digitally-designed and fabricated architecture, it also implies architecture – built form – that can be controlled, actuated, and animated by digital means. In this context, this sixth Footprint issue examines the influence of digital means as prag­matic and conceptual instruments for actuating architecture. The focus is not so much on computer-based systems for the development of architectural designs, but on architecture incorporating digital control, sens­ing, actuating, or other mechanisms that enable buildings to inter­act with their users and surroundings in real time in the real world through physical or sensory change and variation.

  6. Customer-driven competition

    International Nuclear Information System (INIS)

    Taylor, R.

    1996-01-01

    Ontario Hydro's customer-driven strategy, recently approved by Hydro's Executive Board, was described. The strategy is founded on the following components: (1) the dissolution of the Ontario power pool, i.e., the loss of Hydro's franchise monopoly on generation, leaving only power transmission in the hands of the Corporation, (2) divestment of Ontario Hydro's system operations and market operations functions to a new, independent Crown corporation called the Central Market Operator, (3) functional and organizational unbundling of Ontario Hydro into three signature businesses, Genco, Transco, and Retailco, and in the latter two, the functional unbundling of wires from sales and services, (4) a fully commercial Ontario Hydro with normal corporate powers, and (5) a corporate strategy for Ontario Hydro to grow in businesses in an open, symmetrical North American energy market. According to Ontario Hydro management this will allow competition and choice to all customers, have a disciplining effect on prices, and give rise to a retail market of new products and services, while at the same time preserve and enhance the value of public investment in the Corporation

  7. The value (driven) web

    NARCIS (Netherlands)

    Baken, N.H.G.; Wiegel, V.; Van Oortmerssen, G.

    2010-01-01

    This paper presents a vision on the importance of values and ethical aspects in web science. We create(d) the Internet, but now the Internet (technology) is shaping our world increasingly: the way we experience, interact, transact, conduct business et cetera. The Internet is ubiquitous and vital to

  8. Towards Player-Driven Procedural Content Generation

    DEFF Research Database (Denmark)

    Shaker, Noor

    Generating immersive game content is one of the ultimate goals for a game designer. This goal can be achieved taken into account that players’ perceptions of the same game differ according to a number of factors including: players’ personality, playing styles, expertise and cultural background. One...... promising avenue towards optimizing the gameplay experience for individual game players - and thereby attempt to close the affective loop in games - is to automatically tailor the game content in real-time. To realize player-driven procedural content generation one needs to specify the aspects of the game...... that have a key influence on the gameplay experience, identify the relationship between these aspects and player experience and define a mechanism for tailoring the game content to each individual needs. In this dissertation we attempt to address the following research questions towards the aim...

  9. Photonic laser-driven accelerator for GALAXIE

    Energy Technology Data Exchange (ETDEWEB)

    Naranjo, B.; Ho, M.; Hoang, P.; Putterman, S.; Valloni, A.; Rosenzweig, J. B. [UCLA Dept. of Physics and Astronomy Los Angeles, CA 90095-1547 (United States)

    2012-12-21

    We report on the design and development of an all-dielectric laser-driven accelerator to be used in the GALAXIE (GV-per-meter Acce Lerator And X-ray-source Integrated Experiment) project's compact free-electron laser. The approach of our working design is to construct eigenmodes, borrowing from the field of photonics, which yield the appropriate, highly demanding dynamics in a high-field, short wavelength accelerator. Topics discussed include transverse focusing, power coupling, bunching, and fabrication.

  10. Asymptotic work distributions in driven bistable systems

    International Nuclear Information System (INIS)

    Nickelsen, D; Engel, A

    2012-01-01

    The asymptotic tails of the probability distributions of thermodynamic quantities convey important information about the physics of nanoscopic systems driven out of equilibrium. We apply a recently proposed method to analytically determine the asymptotics of work distributions in Langevin systems to an one-dimensional model of single-molecule force spectroscopy. The results are in excellent agreement with numerical simulations, even in the centre of the distributions. We compare our findings with a recent proposal for an universal form of the asymptotics of work distributions in single-molecule experiments.

  11. Recent advances in laser-driven neutron sources

    Science.gov (United States)

    Alejo, A.; Ahmed, H.; Green, A.; Mirfayzi, S. R.; Borghesi, M.; Kar, S.

    2016-11-01

    Due to the limited number and high cost of large-scale neutron facilities, there has been a growing interest in compact accelerator-driven sources. In this context, several potential schemes of laser-driven neutron sources are being intensively studied employing laser-accelerated electron and ion beams. In addition to the potential of delivering neutron beams with high brilliance, directionality and ultra-short burst duration, a laser-driven neutron source would offer further advantages in terms of cost-effectiveness, compactness and radiation confinement by closed-coupled experiments. Some of the recent advances in this field are discussed, showing improvements in the directionality and flux of the laser-driven neutron beams.

  12. Economics-driven software architecture

    CERN Document Server

    Mistrik, Ivan; Kazman, Rick; Zhang, Yuanyuan

    2014-01-01

    Economics-driven Software Architecture presents a guide for engineers and architects who need to understand the economic impact of architecture design decisions: the long term and strategic viability, cost-effectiveness, and sustainability of applications and systems. Economics-driven software development can increase quality, productivity, and profitability, but comprehensive knowledge is needed to understand the architectural challenges involved in dealing with the development of large, architecturally challenging systems in an economic way. This book covers how to apply economic consider

  13. BRAHMMA - accelerator driven subcritical facility

    International Nuclear Information System (INIS)

    Roy, Tushar; Shukla, Shefali; Shukla, M.; Ray, N.K.; Kashyap, Y.S.; Patel, T.; Gadkari, S.C.

    2017-01-01

    Accelerator Driven Subcritical systems are being studied worldwide for their potential in burning minor actinides and reducing long term radiotoxicity of spent nuclear fuels. In order to pursue the physics studies of Accelerator Driven Subcritical systems, a thermal subcritical assembly BRAHMMA (BeOReflectedAndHDPeModeratedMultiplying Assembly) has been developed at Purnima Labs, BARC. The facility consists of two major components: Subcritical core and Accelerator (DT/ DD Purnima Neutron Generator)

  14. MCNPX simulations of fast neutron diagnostics for accelerator-driven systems

    International Nuclear Information System (INIS)

    Habib, Moinul

    2005-12-01

    In accelerator-driven systems, the neutron spectrum will extend all the way up to the incident beam energy, i.e., several hundred MeV or even up to GeV energies. The high neutron energy allows novel diagnostics with a set of measurement techniques that can be used in a sub-critical reactor environment. Such measurements are primarily connected to system safety and validation. This report shows that in-core fast-neutron diagnostics can be employed to monitor changes in the position of incidence of the primary proton beam onto the neutron production target. It has also been shown that fast neutrons can be used to detect temperature-dependent density changes in a liquid lead-bismuth target. Fast neutrons can escape the system via the beam pipe for the incident proton beam. Out-of-core monitoring of these so called back-streaming neutrons could potentially be used to monitor beam changes if the target has a suitable shape. Moreover, diagnostics of back-streaming neutrons might be used for validation of the system design

  15. MCNPX simulations of fast neutron diagnostics for accelerator-driven systems

    Energy Technology Data Exchange (ETDEWEB)

    Habob, Moinul

    2005-12-15

    In accelerator-driven systems, the neutron spectrum will extend all the way up to the incident beam energy, i.e., several hundred MeV or even up to GeV energies. The high neutron energy allows novel diagnostics with a set of measurement techniques that can be used in a sub-critical reactor environment. Such measurements are primarily connected to system safety and validation. This report shows that in-core fast-neutron diagnostics can be employed to monitor changes in the position of incidence of the primary proton beam onto the neutron production target. It has also been shown that fast neutrons can be used to detect temperature-dependent density changes in a liquid lead-bismuth target. Fast neutrons can escape the system via the beam pipe for the incident proton beam. Out-of-core monitoring of these so called back-streaming neutrons could potentially be used to monitor beam changes if the target has a suitable shape. Moreover, diagnostics of back-streaming neutrons might be used for validation of the system design.

  16. Research on transmutation and accelerator-driven systems at the Forschungszentrum Karlsruhe

    International Nuclear Information System (INIS)

    Knebel, J.U.; Heusener, G.

    2000-01-01

    Transmutation is considered a promising technology worldwide for significantly reducing the amount and, thereby, the long-term radiotoxicity of high active waste (HAW) produced by the operation of nuclear power plants such as light water reactors (LWR). The maximum reduction of radiotoxicity could be by a factor of about 100. Transmutation is thus an alternative to the direct deposition of large volumes of highly radioactive waste. Transmutation presents the possibility of closing the fuel cycle including the minor actinides. Plutonium, minor actinides and long-lived fission products can be transmuted in a so called Accelerator Driven Sub-critical System (ADS), which consists of an accelerator, a target module and a subcritical blanket. This paper describes the work performed at Forschungszentrum Karlsruhe which is critically evaluating an ADS mainly with respect to its potential for transmuting minor actinides, to its feasibility and to safety aspects. The work is being done in the area of core design, neutronics, safety, system analyses, materials and corrosion. (orig.) [de

  17. A new option for exploitage of future nuclear energy. Accelerator driven radioactive clean nuclear power system

    International Nuclear Information System (INIS)

    Ding Dazhao

    2000-01-01

    Nuclear energy is an effective, clean and safe energy resource. But some shortages of the nuclear energy system presently commercial available obstruct further development of the nuclear energy by heavy nuclear fission. Those are final disposal of the high level radioactive waste, inefficient use of the uranium resource and safety issue of the system. Innovative technical option is seeking for by the nuclear scientific community in recent ten years in aiming to overcome these obstacles, namely, accelerator driven sub-critical system (ADS). This hybrid system may bridge over the gap between presently commercial available nuclear power system and the full exploitation of the fusion energy. The basic principle of ADS is described and its capability in waste transmutation, conversion of the nuclear fuel are demonstrated by two examples--AD-fast reactor and AD-heavy water thermal reactor. The feasibility of ADS and some projects in US, Japan, etc are briefly discussed. The rationale in promoting the R and D of ADS in China is emphasized as China is at the beginning stage of its ambitious project in construction of the nuclear power

  18. Accelerator-driven systems (ADS) and fast reactors (FR) in advanced nuclear fuel cycles

    International Nuclear Information System (INIS)

    2002-01-01

    The long-term hazard of radioactive waste arising from nuclear energy production is a matter of continued discussion and public concern in many countries. Through partitioning and transmutation (P and T) of the actinides and some of the long-lived fission products, the radiotoxicity of high-level waste (HLW) can be reduced by a factor of 100 compared with the current once-through fuel cycle. This requires very effective reactor and fuel cycle strategies, including fast reactors (FR) and/or accelerator-driven, sub-critical systems (ADS). The present study compares FR- and ADS-based actinide transmutation systems with respect to reactor properties, fuel cycle requirements, safety, economic aspects and (R and D) needs. Several advanced fuel cycle strategies are analysed in a consistent manner to provide insight into the essential differences between the various systems in which the role of ADS is emphasised. The report includes a summary aimed at policy makers and research managers as well as a detailed technical section for experts in this domain. (authors)

  19. The Approach of Blended Learning to cope with E and T Needs in the Nuclear Engineering Field in an International Environmental. The experience of the Design and Implementation of a Distance Pilot Course on Accelerator Driven Systems within FP7 ENEN III Project Framework

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, M.; Gonzalez, E. M.; Sanz, J.; Ogando, F.; Sanchez-Elvira, A.

    2013-07-01

    In these days Education and Training (Eand T) worldwide is redirecting towards the design of a balanced combination of face-to-face and distance teaching, taking advantage of the new tools for Information and Communication Technologies (ICT), in what we know as blended learning. Our University is been devoted to blended learning already for 41 years, Thus, our participation in FP7 ENEN III project gave us the opportunity to offer distance teaching and learning for international EandT in the nuclear field taking into account UNED long experience. The development of ENEN III Training Schemes (TS) highlighted a significant lack of international courses in TS-D: Concepts and Design of GEN IV nuclear reactors. Additionally, no distance course was offered. Our long collaboration UNED-CIEMAT on Accelerator Driven Systems (ADS) and the support of our Instituto Universitario de Educacion a Distancia (IUED), experts in online teaching and learning, moved us to develop the full-distance international course Accelerator Driven Systems for advanced nuclear waste transmutation, within the project framework.

  20. The Approach of Blended Learning to cope with E and T Needs in the Nuclear Engineering Field in an International Environmental. The experience of the Design and Implementation of a Distance Pilot Course on Accelerator Driven Systems within FP7 ENEN III Project Framework

    International Nuclear Information System (INIS)

    Alonso, M.; Gonzalez, E. M.; Sanz, J.; Ogando, F.; Sanchez-Elvira, A.

    2013-01-01

    In these days Education and Training (Eand T) worldwide is redirecting towards the design of a balanced combination of face-to-face and distance teaching, taking advantage of the new tools for Information and Communication Technologies (ICT), in what we know as blended learning. Our University is been devoted to blended learning already for 41 years, Thus, our participation in FP7 ENEN III project gave us the opportunity to offer distance teaching and learning for international EandT in the nuclear field taking into account UNED long experience. The development of ENEN III Training Schemes (TS) highlighted a significant lack of international courses in TS-D: Concepts and Design of GEN IV nuclear reactors. Additionally, no distance course was offered. Our long collaboration UNED-CIEMAT on Accelerator Driven Systems (ADS) and the support of our Instituto Universitario de Educacion a Distancia (IUED), experts in online teaching and learning, moved us to develop the full-distance international course Accelerator Driven Systems for advanced nuclear waste transmutation, within the project framework.

  1. System for prediction and determination of the sub critic multiplication

    International Nuclear Information System (INIS)

    Martinez, Aquilino S.; Pereira, Valmir; Silva, Fernando C. da

    1997-01-01

    It is presented a concept of a system which may be used to calculate and anticipate the subcritical multiplication of a PWR nuclear power plant. The system is divided into two different modules. The first module allows the theoretical prediction of the subcritical multiplication factor through the solution of the multigroup diffusion equation. The second module determines this factor based on the data acquired from the neutron detectors of a NPP external nuclear detection system. (author). 3 refs., 3 figs., 2 tabs

  2. Comparative analysis of sub-critical transmutation reactor concepts

    International Nuclear Information System (INIS)

    Chang, S. H.

    1997-01-01

    The long-lived nuclear wastes have been substantially generated from the light water reactor for a few decades. The toxicity of these spent fuels will be higher than that of the uranium ore, even if those will be stored in the repository more than ten thousands. Hence the means of transmuting the key long-lived nuclear wastes, primarily the minor actinides, using a hybrid proton accelerator and subcritical transmutation reactor, are proposed. Until now, the representative concepts for a subcritical transmutation reactor are the Energy Amplifier, the OMEGA project, the ATW and the MSBR. The detailed concepts and the specifications are illustrated in Table 1. The design requirements for the subcritical transmutation reactor are the high transmutation rate of long-lived nuclear wastes, safety and economics. And to propose the subcritical transmutation reactor concepts, the coolant, the target material and fuel type are carefully considered. In these aspects, the representative concepts for a subcritical transmutation reactor in Table 1 have been surveyed. The requirements for a target and a coolant are the reliable, low maintenance operation and safe operation to minimize the wastes. The reliable, low maintenance operation and safe operation to minimize the wastes. The reliable coolant must have the low melting point, high heat capacity and excellent physical properties. And the target material must have high neutron yield for a given proton condition and easy heat removal capability. Therefore in respect with the above requirements, Pb-Bi is proposed as the coolant and the target material for the subcritical reactor. Because the neutron yield for a given proton energy increases linearly with mass number up to bismuth but in heavier elements spallation events sharply increase both the neutron and heat outputs, Pb-Bi meets not only such the requirements as the above for the coolant but also those for the coolant and target, the simplification of system can be achieved. Therefore, Pb-Bi is proposed as the coolant and the target material for a subcritical transmutation reactor. (author)

  3. A microfluidic sub-critical water extraction instrument

    Science.gov (United States)

    Sherrit, Stewart; Noell, Aaron C.; Fisher, Anita; Lee, Mike C.; Takano, Nobuyuki; Bao, Xiaoqi; Kutzer, Thomas C.; Grunthaner, Frank

    2017-11-01

    This article discusses a microfluidic subcritical water extraction (SCWE) chip for autonomous extraction of amino acids from astrobiologically interesting samples. The microfluidic instrument is composed of three major components. These include a mixing chamber where the soil sample is mixed and agitated with the solvent (water), a subcritical water extraction chamber where the sample is sealed with a freeze valve at the chip inlet after a vapor bubble is injected into the inlet channels to ensure the pressure in the chip is in equilibrium with the vapor pressure and the slurry is then heated to ≤200 °C in the SCWE chamber, and a filter or settling chamber where the slurry is pumped to after extraction. The extraction yield of the microfluidic SCWE chip process ranged from 50% compared to acid hydrolysis and 80%-100% compared to a benchtop microwave SCWE for low biomass samples.

  4. From current-driven to neoclassically driven tearing modes.

    Science.gov (United States)

    Reimerdes, H; Sauter, O; Goodman, T; Pochelon, A

    2002-03-11

    In the TCV tokamak, the m/n = 2/1 island is observed in low-density discharges with central electron-cyclotron current drive. The evolution of its width has two distinct growth phases, one of which can be linked to a "conventional" tearing mode driven unstable by the current profile and the other to a neoclassical tearing mode driven by a perturbation of the bootstrap current. The TCV results provide the first clear observation of such a destabilization mechanism and reconcile the theory of conventional and neoclassical tearing modes, which differ only in the dominant driving term.

  5. Laser driven particle acceleration

    International Nuclear Information System (INIS)

    Faure, J.

    2009-06-01

    This dissertation summarizes the last ten years of research at the Laboratory of Applied Optics on laser-plasma based electron acceleration. The main result consists of the development and study of a relativistic electron source with unique properties: high energy (100-300 MeV) in short distances (few millimeters), mono-energetic, ultra-short (few fs), stable and tunable. The manuscript describes the steps that led to understanding the physics, and then mastering it in order to produce this new electron source. Non linear propagation of the laser pulse in the plasma is first presented, with phenomena such as non linear wakefield excitation, relativistic and ponderomotive self-focusing in the short pulse regime, self-compression. Acceleration and injection of electrons are then reviewed from a theoretical perspective. Experimental demonstrations of self-injection in the bubble regime and then colliding pulse injection are then presented. These experiments were among the first to produce monoenergetic, high quality, stable and tunable electron beams from a laser-plasma accelerator. The last two chapters are dedicated to the characterization of the electron beam using transition radiation and to its applications to gamma radiography and radiotherapy. Finally, the perspectives of this research are presented in the conclusion. Scaling laws are used to determine the parameters that the electron beams will reach using peta-watt laser systems currently under construction. (author)

  6. Limits on the generalizability of context-driven control.

    Science.gov (United States)

    Hutcheon, Thomas G; Spieler, Daniel H

    2017-07-01

    Context-driven control refers to the fast and flexible weighting of stimulus dimensions that may be applied at the onset of a stimulus. Evidence for context-driven control comes from interference tasks in which participants encounter a high proportion of incongruent trials at one location and a high proportion of congruent trials at another location. Since the size of the congruency effect varies as a function of location, this suggests that stimulus dimensions are weighted differently based on the context in which they appear. However, manipulations of condition proportion are often confounded by variations in the frequency with which particular stimuli are encountered. To date, there is limited evidence for the context-driven control in the absence of stimulus frequency confounds. In the current paper, we attempt to replicate and extend one such finding [Crump, M. J. C., & Milliken, B. (2009). The flexibility of context-specific control: Evidence for context-driven generalization of item-specific control settings. The Quarterly Journal of Experimental Psychology, 62, 1523-1532]. Across three experiments we fail to find evidence for context-driven control in the absence of stimulus frequency confounds. Based on these results, we argue that consistency in the informativeness of the irrelevant dimension may be required for context-driven control to emerge.

  7. Data-driven batch schuduling

    Energy Technology Data Exchange (ETDEWEB)

    Bent, John [Los Alamos National Laboratory; Denehy, Tim [GOOGLE; Arpaci - Dusseau, Remzi [UNIV OF WISCONSIN; Livny, Miron [UNIV OF WISCONSIN; Arpaci - Dusseau, Andrea C [NON LANL

    2009-01-01

    In this paper, we develop data-driven strategies for batch computing schedulers. Current CPU-centric batch schedulers ignore the data needs within workloads and execute them by linking them transparently and directly to their needed data. When scheduled on remote computational resources, this elegant solution of direct data access can incur an order of magnitude performance penalty for data-intensive workloads. Adding data-awareness to batch schedulers allows a careful coordination of data and CPU allocation thereby reducing the cost of remote execution. We offer here new techniques by which batch schedulers can become data-driven. Such systems can use our analytical predictive models to select one of the four data-driven scheduling policies that we have created. Through simulation, we demonstrate the accuracy of our predictive models and show how they can reduce time to completion for some workloads by as much as 80%.

  8. Knowledge-Driven Versus Data-Driven Logics

    Czech Academy of Sciences Publication Activity Database

    Dubois, D.; Hájek, Petr; Prade, H.

    2000-01-01

    Roč. 9, č. 1 (2000), s. 65-89 ISSN 0925-8531 R&D Projects: GA AV ČR IAA1030601 Grant - others:CNRS(FR) 4008 Institutional research plan: AV0Z1030915 Keywords : epistemic logic * possibility theory * data-driven reasoning * deontic logic Subject RIV: BA - General Mathematics

  9. Stimulus-driven attentional capture by subliminal onset cues

    NARCIS (Netherlands)

    Schoeberl, T.; Fuchs, I.; Theeuwes, J.; Ansorge, U.

    2015-01-01

    In two experiments, we tested whether subliminal abrupt onset cues capture attention in a stimulus-driven way. An onset cue was presented 16 ms prior to the stimulus display that consisted of clearly visible color targets. The onset cue was presented either at the same side as the target (the valid

  10. Temperature driven transport of gold nanoparticles physisorbed inside carbon nanotubes

    DEFF Research Database (Denmark)

    Schoen, P.A.E.; Poulikakos, D.; Walther, Jens Honore

    2006-01-01

    We use molecular dynamics simulations to demonstrate the temperature driven mass transport of solid gold nanoparticles, physisorbed inside carbon nanotubes (CNTs). Our results indicate that the nanoparticle experiences a guided motion, in the direction opposite to the direction of the temperature...... affects the nanoparticle motion along the carbon lattice....

  11. Powerful FEM-generator driven by microsecond sheet beam

    Energy Technology Data Exchange (ETDEWEB)

    Agafonov, M A; Arzhannikov, A V; Sinitskij, S L; Tarasov, A V [Institute of Nuclear Physics, Novosibirsk (Russian Federation); Ginzburg, N S; Peskov, N Yu [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)

    1997-12-31

    The results of experimental and theoretical investigations in the creation of a powerful mm-band generator driven by a sheet beam are presented. A microsecond pulse of mm-radiation with a 200 J energy content was obtained in the experiments. The possibility of increasing this energy content up to tens of kJ was demonstrated. 3 figs., 8 refs.

  12. Guilt driven reciprocity in a psychological signaling game

    NARCIS (Netherlands)

    Fong, Y.; Huang, C.-Y.; Offerman, T.

    2007-01-01

    We propose a theory of reciprocity according to which reciprocal behavior is driven by a donor's guilt. Through an experiment we show that subjects respond to factors which induce guilt but do not reflect allocative equity or intention. When the guilt inducing factor is privately observed by the

  13. Guilt driven reciprocity in a psychological signaling game

    NARCIS (Netherlands)

    Fong, Y.; Huang, C.-Y.; Offerman, T.

    2009-01-01

    We propose a theory of reciprocity according to which reciprocal behavior is driven by a donor’s guilt. Through an experiment we show that subjects respond to factors which induce guilt but do not reflect allocative equity or intention. When the guilt inducing factor is privately observed by the

  14. Mixed signals: The effect of conflicting reward- and goal-driven biases on selective attention.

    Science.gov (United States)

    Preciado, Daniel; Munneke, Jaap; Theeuwes, Jan

    2017-07-01

    Attentional selection depends on the interaction between exogenous (stimulus-driven), endogenous (goal-driven), and selection history (experience-driven) factors. While endogenous and exogenous biases have been widely investigated, less is known about their interplay with value-driven attention. The present study investigated the interaction between reward-history and goal-driven biases on perceptual sensitivity (d') and response time (RT) in a modified cueing paradigm presenting two coloured cues, followed by sinusoidal gratings. Participants responded to the orientation of one of these gratings. In Experiment 1, one cue signalled reward availability but was otherwise task irrelevant. In Experiment 2, the same cue signalled reward, and indicated the target's most likely location at the opposite side of the display. This design introduced a conflict between reward-driven biases attracting attention and goal-driven biases directing it away. Attentional effects were examined comparing trials in which cue and target appeared at the same versus opposite locations. Two interstimulus interval (ISI) levels were used to probe the time course of attentional effects. Experiment 1 showed performance benefits at the location of the reward-signalling cue and costs at the opposite for both ISIs, indicating value-driven capture. Experiment 2 showed performance benefits only for the long ISI when the target was at the opposite to the reward-associated cue. At the short ISI, only performance costs were observed. These results reveal the time course of these biases, indicating that reward-driven effects influence attention early but can be overcome later by goal-driven control. This suggests that reward-driven biases are integrated as attentional priorities, just as exogenous and endogenous factors.

  15. Effects of N source concentration and NH4(+)/NO3(-) ratio on phenylethanoid glycoside pattern in tissue cultures of Plantago lanceolata L.: a metabolomics driven full-factorial experiment with LC-ESI-MS(3.).

    Science.gov (United States)

    Gonda, Sándor; Kiss-Szikszai, Attila; Szűcs, Zsolt; Máthé, Csaba; Vasas, Gábor

    2014-10-01

    Tissue cultures of a medicinal plant, Plantago lanceolata L. were screened for phenylethanoid glycosides (PGs) and other natural products (NPs) with LC-ESI-MS(3). The effects of N source concentration and NH4(+)/NO3(-) ratio were evaluated in a full-factorial (FF) experiment. N concentrations of 10, 20, 40 and 60mM, and NH4(+)/NO3(-) ratios of 0, 0.11, 0.20 and 0.33 (ratio of NH4(+) in total N source) were tested. Several peaks could be identified as PGs, of which, 16 could be putatively identified from the MS/MS/MS spectra. N source concentration and NH4(+)/NO3(-) ratio had significant effects on the metabolome, their effects on individual PGs were different despite these metabolites were of the same biosynthethic class. Chief PGs were plantamajoside and acteoside (verbascoside), their highest concentrations were 3.54±0.83% and 1.30±0.40% of dry weight, on media 10(0.33) and 40(0.33), respectively. NH4(+)/NO3(-) ratio and N source concentration effects were examined on a set of 89 NPs. For most NPs, high increases in abundance were observed compared to Murashige-Skoog medium. Abundances of 42 and 10 NPs were significantly influenced by the N source concentration and the NH4(+)/NO3(-) ratio, respectively. Optimal media for production of different NP clusters were 10(0), 10(0.11) and 40(0.33). Interaction was observed between NH4(+)/NO3(-) ratio and N source concentration for many NPs. It was shown in simulated experiments, that one-factor at a time (OFAT) experimental designs lead to sub-optimal media compositions for production of many NPs, and alternative experimental designs (e.g. FF) should be preferred when optimizing medium N source for optimal yield of NPs. If using OFAT, the N source concentration is to be optimized first, followed by NH4(+)/NO3(-) ratio, as this reduces the likeliness of suboptimal yield results. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Entropy-driven phase transitions

    NARCIS (Netherlands)

    Frenkel, D.

    1999-01-01

    Increase in visible order can be associated with an increase in microscopic disorder. This phenomenon leads to many counter-intuitive phenomena such as entropy driven crystallization and phase separation. I devote special attention to the entropic depletion interaction as a means to tune the range

  17. Model-driven software engineering

    NARCIS (Netherlands)

    Amstel, van M.F.; Brand, van den M.G.J.; Protic, Z.; Verhoeff, T.; Hamberg, R.; Verriet, J.

    2014-01-01

    Software plays an important role in designing and operating warehouses. However, traditional software engineering methods for designing warehouse software are not able to cope with the complexity, size, and increase of automation in modern warehouses. This chapter describes Model-Driven Software

  18. Typology of customer driven manufacturing

    NARCIS (Netherlands)

    Wortmann, J.C.; Wortmann, J.C.; Muntslag, D.R.; Timmermans, P.J.M.

    1997-01-01

    The aim of this chapter has been to introduce a variety of customer driven manufacturing situations. This variety has been placed in a two-dimensional grid, which constitutes a typology. For some of these types, production management issues were discussed in section 6.3. It was concluded that an

  19. Work(er)-Driven Innovation

    Science.gov (United States)

    Smith, Raymond

    2017-01-01

    Purpose: The focus on innovation as a foundational element of enhanced organisational performance has led to the promoting and valuing of greater levels of employee participation in innovation processes. An emergent concept of employee-driven innovation could be argued to have hindered understandings of the creative and transformative nature of…

  20. Synchrotron-driven spallation sources

    CERN Document Server

    Bryant, P J

    1996-01-01

    The use of synchrotrons for pulsed neutron spallation sources is an example of scientific and technological spin-off from the accelerator development for particle physics. Accelerator-driven sources provide an alternative to the continuous-flux, nuclear reactors that currently furnish the majority of neutrons for research and development. Although the present demand for neutrons can be adequately met by the existing reactors, this situation is unlikely to continue due to the increasing severity of safety regulations and the declared policies of many countries to close down their reactors within the next decade or so. Since the demand for neutrons as a research tool is, in any case,expected to grow, there has been a corresponding interest in sources that are synchrotron-driven or linac-driven with a pulse compression ring and currently several design studies are being made. These accelerator-driven sources also have the advantage of a time structure with a high peak neutron flux. The basic requirement is for a...

  1. PC driven integrated vacuum system

    International Nuclear Information System (INIS)

    Curuia, M.; Culcer, M.; Brandea, I.; Anghel, M.

    2001-01-01

    The paper presents a integrated vacuum system which was designed and manufactured in our institute. The main parts of this system are the power supply unit for turbo-melecular pumps and the vacuummeter. Both parts of the system are driven by means of a personal computer using a serial communication, according to the RS 232 hardware standard.(author)

  2. Smart energy households' pilot projects in the Netherlands with a design-driven approach

    NARCIS (Netherlands)

    Geelen, D.V.; Scheepens, A.; Kobus, C.; Obinna, U.; Mugge, R.; Schoormans, J.; Reinders, Angelina H.M.E.

    2013-01-01

    Residential smart grid projects can be evaluated by a design-driven approach, which focuses on gaining insights for successful product and service development by taking the end-users as a starting point. Because only little experience exists with this design-driven approach, this paper addresses how

  3. Hysteresis in pressure-driven DNA denaturation.

    Directory of Open Access Journals (Sweden)

    Enrique Hernández-Lemus

    Full Text Available In the past, a great deal of attention has been drawn to thermal driven denaturation processes. In recent years, however, the discovery of stress-induced denaturation, observed at the one-molecule level, has revealed new insights into the complex phenomena involved in the thermo-mechanics of DNA function. Understanding the effect of local pressure variations in DNA stability is thus an appealing topic. Such processes as cellular stress, dehydration, and changes in the ionic strength of the medium could explain local pressure changes that will affect the molecular mechanics of DNA and hence its stability. In this work, a theory that accounts for hysteresis in pressure-driven DNA denaturation is proposed. We here combine an irreversible thermodynamic approach with an equation of state based on the Poisson-Boltzmann cell model. The latter one provides a good description of the osmotic pressure over a wide range of DNA concentrations. The resulting theoretical framework predicts, in general, the process of denaturation and, in particular, hysteresis curves for a DNA sequence in terms of system parameters such as salt concentration, density of DNA molecules and temperature in addition to structural and configurational states of DNA. Furthermore, this formalism can be naturally extended to more complex situations, for example, in cases where the host medium is made up of asymmetric salts or in the description of the (helical-like charge distribution along the DNA molecule. Moreover, since this study incorporates the effect of pressure through a thermodynamic analysis, much of what is known from temperature-driven experiments will shed light on the pressure-induced melting issue.

  4. Transport Barriers in Bootstrap Driven Tokamaks

    Science.gov (United States)

    Staebler, Gary

    2017-10-01

    Maximizing the bootstrap current in a tokamak, so that it drives a high fraction of the total current, reduces the external power required to drive current by other means. Improved energy confinement, relative to empirical scaling laws, enables a reactor to more fully take advantage of the bootstrap driven tokamak. Experiments have demonstrated improved energy confinement due to the spontaneous formation of an internal transport barrier in high bootstrap fraction discharges. Gyrokinetic analysis, and quasilinear predictive modeling, demonstrates that the observed transport barrier is due to the suppression of turbulence primarily due to the large Shafranov shift. ExB velocity shear does not play a significant role in the transport barrier due to the high safety factor. It will be shown, that the Shafranov shift can produce a bifurcation to improved confinement in regions of positive magnetic shear or a continuous reduction in transport for weak or negative magnetic shear. Operation at high safety factor lowers the pressure gradient threshold for the Shafranov shift driven barrier formation. The ion energy transport is reduced to neoclassical and electron energy and particle transport is reduced, but still turbulent, within the barrier. Deeper into the plasma, very large levels of electron transport are observed. The observed electron temperature profile is shown to be close to the threshold for the electron temperature gradient (ETG) mode. A large ETG driven energy transport is qualitatively consistent with recent multi-scale gyrokinetic simulations showing that reducing the ion scale turbulence can lead to large increase in the electron scale transport. A new saturation model for the quasilinear TGLF transport code, that fits these multi-scale gyrokinetic simulations, can match the data if the impact of zonal flow mixing on the ETG modes is reduced at high safety factor. This work was supported by the U.S. Department of Energy under DE-FG02-95ER54309 and DE-FC02

  5. Pulsed power driven hohlraum research at Sandia National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Leeper, R J; Alberts, T E; Allshouse, G A [Sandia Labs., Albuquerque, NM (United States); and others

    1997-12-31

    Three pulsed power driven hohlraum concepts are being investigated at Sandia National Laboratories. These hohlraums are driven by intense proton and Li ion beams as well as by two different types of z-pinch x-ray sources. The paper is an overview of the experiments that have been conducted on these hohlraum systems and discusses several new and novel hohlraum characterization diagnostics that have been developed for this work. These diagnostics include an active shock breakout measurement of hohlraum temperature and a new transmission grating spectrograph for detailed thermal radiation spectral measurements. (author). 3 figs., 6 refs.

  6. Pulsed power driven hohlraum research at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Leeper, R.J.; Alberts, T.E.; Allshouse, G.A.

    1996-01-01

    Three pulsed power driven hohlraum concepts are being investigated at Sandia National Laboratories. These hohlraums are driven by intense proton and Li ion beams as well as by two different types of z-pinch x-ray sources. The paper is an overview of the experiments that have been conducted on these hohlraum systems and discusses several new and novel hohlraum characterization diagnostics that have been developed for this work. These diagnostics include an active shock breakout measurement of hohlraum temperature and a new transmission grating spectrograph for detailed thermal radiation spectral measurements. (author). 3 figs., 6 refs

  7. System and safety studies of accelerator driven transmutation. Annual Report 2002

    International Nuclear Information System (INIS)

    Gudowski, W.; Wallenius, J.; Tucek, K.; Eriksson, Marcus; Carlsson, Johan; Seltborg, P.; Cetnar, J.; Chakarova, R.; Jollkonen, Mikael; Westlen, D.

    2003-06-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the Dept. of Nuclear and Reactor Physics has been largely determined by the program of the European projects of the the 5th Framework Programme. In particular: a) ADS core design and development of advanced nuclear fuel optimized for high transmutation rates and good safety features. This activity includes computer modeling of nuclear fuel production. Three different ADS-core concept are being investigated: Conceptual design of Pb-Bi cooled core with nitride fuel - so called Sing-Sing Core; Pb-Bi cooled core with oxide fuel; Gas cooled core with oxide fuel - both designs investigated for the European Project PDS-XADS; b) analysis of ADS-dynamics and assessment of major reactivity feedbacks; c) emergency heat removal from ADS; d) participation in ADS experiments including 1 MW spallation target manufacturing, subcritical experiments MUSE, YALINA subcritical experiment in Minsk and designing of the subcritical experiment SAD in Dubna; e) material studies for ADS, in particular theoretical and simulation studies of radiation damage in high neutron (or proton) fluxes; f) computer code and nuclear data development relevant for simulation and optimization of ADS, special efforts were put in the frame of the European Project PDS-XADS to perform sensitivity studies of the different nuclear data libraries; g) studies of transmutation potential of critical reactors in particular High Temp Gas Cooled Reactor. Most important finding and conclusions from our studies: A strong positive void coefficient was found for lead/bismuth cooled cores. This considerable void effect is attributed to a high fraction of americium (60%) in the fuel. It was found that void reactivity insertion rates increases with P/D; in response to the beam overpower accident the Pb/Bi-cooled core featured the twice longer grace time compared to the sodium-cooled core; an important safety issue is the high void worth that could

  8. Data-driven modeling of nano-nose gas sensor arrays

    DEFF Research Database (Denmark)

    Alstrøm, Tommy Sonne; Larsen, Jan; Nielsen, Claus Højgård

    2010-01-01

    We present a data-driven approach to classification of Quartz Crystal Microbalance (QCM) sensor data. The sensor is a nano-nose gas sensor that detects concentrations of analytes down to ppm levels using plasma polymorized coatings. Each sensor experiment takes approximately one hour hence...... the number of available training data is limited. We suggest a data-driven classification model which work from few examples. The paper compares a number of data-driven classification and quantification schemes able to detect the gas and the concentration level. The data-driven approaches are based on state...

  9. Data–driven modeling of nano-nose gas sensor arrays

    DEFF Research Database (Denmark)

    Alstrøm, Tommy Sonne; Larsen, Jan; Nielsen, Claus Højgård

    2010-01-01

    We present a data-driven approach to classification of Quartz Crystal Microbalance (QCM) sensor data. The sensor is a nano-nose gas sensor that detects concentrations of analytes down to ppm levels using plasma polymorized coatings. Each sensor experiment takes approximately one hour hence...... the number of available training data is limited. We suggest a data-driven classification model which work from few examples. The paper compares a number of data-driven classification and quantification schemes able to detect the gas and the concentration level. The data-driven approaches are based on state...

  10. Quantitative theory of driven nonlinear brain dynamics.

    Science.gov (United States)

    Roberts, J A; Robinson, P A

    2012-09-01

    Strong periodic stimuli such as bright flashing lights evoke nonlinear responses in the brain and interact nonlinearly with ongoing cortical activity, but the underlying mechanisms for these phenomena are poorly understood at present. The dominant features of these experimentally observed dynamics are reproduced by the dynamics of a quantitative neural field model subject to periodic drive. Model power spectra over a range of drive frequencies show agreement with multiple features of experimental measurements, exhibiting nonlinear effects including entrainment over a range of frequencies around the natural alpha frequency f(α), subharmonic entrainment near 2f(α), and harmonic generation. Further analysis of the driven dynamics as a function of the drive parameters reveals rich nonlinear dynamics that is predicted to be observable in future experiments at high drive amplitude, including period doubling, bistable phase-locking, hysteresis, wave mixing, and chaos indicated by positive Lyapunov exponents. Moreover, photosensitive seizures are predicted for physiologically realistic model parameters yielding bistability between healthy and seizure dynamics. These results demonstrate the applicability of neural field models to the new regime of periodically driven nonlinear dynamics, enabling interpretation of experimental data in terms of specific generating mechanisms and providing new tests of the theory. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Progress of Laser-Driven Plasma Accelerators

    International Nuclear Information System (INIS)

    Nakajima, Kazuhisa

    2007-01-01

    There is a great interest worldwide in plasma accelerators driven by ultra-intense lasers which make it possible to generate ultra-high gradient acceleration and high quality particle beams in a much more compact size compared with conventional accelerators. A frontier research on laser and plasma accelerators is focused on high energy electron acceleration and ultra-short X-ray and Tera Hertz radiations as their applications. These achievements will provide not only a wide range of sciences with benefits of a table-top accelerator but also a basic science with a tool of ultrahigh energy accelerators probing an unknown extremely microscopic world.Harnessing the recent advance of ultra-intense ultra-short pulse lasers, the worldwide research has made a tremendous breakthrough in demonstrating high-energy high-quality particle beams in a compact scale, so called ''dream beams on a table top'', which represents monoenergetic electron beams from laser wakefield accelerators and GeV acceleration by capillary plasma-channel laser wakefield accelerators. This lecture reviews recent progress of results on laser-driven plasma based accelerator experiments to quest for particle acceleration physics in intense laser-plasma interactions and to present new outlook for the GeV-range high-energy laser plasma accelerators

  12. Accelerating Science Driven System Design With RAMP

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzynek, John [Univ. of California, Berkeley, CA (United States)

    2015-05-01

    Researchers from UC Berkeley, in collaboration with the Lawrence Berkeley National Lab, are engaged in developing an Infrastructure for Synthesis with Integrated Simulation (ISIS). The ISIS Project was a cooperative effort for “application-driven hardware design” that engages application scientists in the early parts of the hardware design process for future generation supercomputing systems. This project served to foster development of computing systems that are better tuned to the application requirements of demanding scientific applications and result in more cost-effective and efficient HPC system designs. In order to overcome long conventional design-cycle times, we leveraged reconfigurable devices to aid in the design of high-efficiency systems, including conventional multi- and many-core systems. The resulting system emulation/prototyping environment, in conjunction with the appropriate intermediate abstractions, provided both a convenient user programming experience and retained flexibility, and thus efficiency, of a reconfigurable platform. We initially targeted the Berkeley RAMP system (Research Accelerator for Multiple Processors) as that hardware emulation environment to facilitate and ultimately accelerate the iterative process of science-driven system design. Our goal was to develop and demonstrate a design methodology for domain-optimized computer system architectures. The tangible outcome is a methodology and tools for rapid prototyping and design-space exploration, leading to highly optimized and efficient HPC systems.

  13. Test Driven Development of Scientific Models

    Science.gov (United States)

    Clune, Thomas L.

    2012-01-01

    Test-Driven Development (TDD) is a software development process that promises many advantages for developer productivity and has become widely accepted among professional software engineers. As the name suggests, TDD practitioners alternate between writing short automated tests and producing code that passes those tests. Although this overly simplified description will undoubtedly sound prohibitively burdensome to many uninitiated developers, the advent of powerful unit-testing frameworks greatly reduces the effort required to produce and routinely execute suites of tests. By testimony, many developers find TDD to be addicting after only a few days of exposure, and find it unthinkable to return to previous practices. Of course, scientific/technical software differs from other software categories in a number of important respects, but I nonetheless believe that TDD is quite applicable to the development of such software and has the potential to significantly improve programmer productivity and code quality within the scientific community. After a detailed introduction to TDD, I will present the experience within the Software Systems Support Office (SSSO) in applying the technique to various scientific applications. This discussion will emphasize the various direct and indirect benefits as well as some of the difficulties and limitations of the methodology. I will conclude with a brief description of pFUnit, a unit testing framework I co-developed to support test-driven development of parallel Fortran applications.

  14. Transport barriers in bootstrap-driven tokamaks

    Science.gov (United States)

    Staebler, G. M.; Garofalo, A. M.; Pan, C.; McClenaghan, J.; Van Zeeland, M. A.; Lao, L. L.

    2018-05-01

    Experiments have demonstrated improved energy confinement due to the spontaneous formation of an internal transport barrier in high bootstrap fraction discharges. Gyrokinetic analysis, and quasilinear predictive modeling, demonstrates that the observed transport barrier is caused by the suppression of turbulence primarily from the large Shafranov shift. It is shown that the Shafranov shift can produce a bifurcation to improved confinement in regions of positive magnetic shear or a continuous reduction in transport for weak or negative magnetic shear. Operation at high safety factor lowers the pressure gradient threshold for the Shafranov shift-driven barrier formation. Two self-organized states of the internal and edge transport barrier are observed. It is shown that these two states are controlled by the interaction of the bootstrap current with magnetic shear, and the kinetic ballooning mode instability boundary. Election scale energy transport is predicted to be dominant in the inner 60% of the profile. Evidence is presented that energetic particle-driven instabilities could be playing a role in the thermal energy transport in this region.

  15. Current and noise in driven heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, Franz

    2009-02-18

    In this thesis we consider the electron transport in nanoscale systems driven by an external energy source. We introduce a tight-binding Hamiltonian containing an interaction term that describes a very strong Coulomb repulsion between electrons in the system. Since we deal with time-dependent situations, we employ a Floquet theory to take into account the time periodicity induced by different external oscillating fields. For the two-level system, we even provide an analytical solution for the eigenenergies with arbitrary phase shift between the levels for a cosine-shaped driving. To describe time-dependent driven transport, we derive a master equation by tracing out the influence of the surrounding leads in order to obtain the reduced density operator of the system. We generalise the common master equation for the reduced density operator to perform an analysis of the noise characteristics. The concept of Full Counting Statistics in electron transport gained much attention in recent years proven its value as a powerful theoretical technique. Combining its advantages with the master equation approach, we find a hierarchy in the moments of the electron number in one lead that allows us to calculate the first two cumulants. The first cumulant can be identified as the current passing through the system, while the noise of this transmission process is reflected by the second cumulant. Moreover, in combination with our Floquet approach, the formalism is not limited to static situations, which we prove by calculating the current and noise characteristics for the non-adiabatic electron pump. We study the influence of a static energy disorder on the maximal possible current for different realisations. Further, we explore the possibility of non-adiabatically pumping electrons in an initially symmetric system if random fluctuations break this symmetry. Motivated by recent and upcoming experiments, we use our extended Floquet model to properly describe systems driven by

  16. The Permanent Magnet Operating Mechanism of Double Coil Parallel Driven at a High Speed

    Directory of Open Access Journals (Sweden)

    WEI Xau-Lao

    2017-02-01

    Full Text Available Abstract:Operating mechanism is the main part of breaker,and the quality of breaker will directly influence the safe operation of power system. Because of the continuous improvement requirements of switch,in order to mak this actuator faster and more powerful closing,this paper proposes a double coil parallel driven permanent magnet actuator at a high speed. This paper expounds the working principle of single and double coil parallel driven permanent magnet actuator. It uses Ansoft building model and contrasts test results. In prance we designed and produced the single and double coil parallel driven permanent magnet actuator for experimental study. The simulation and experiment results show that double coil parallel driven permanent magnet actuator,compared with single coil parallel driven permanent magnet actuator,has a better and faster action performance. Thus,the double coil parallel driven permanent magnet actuator achieves a kind of optimization.

  17. Phase transformations and systems driven far from equilibrium

    International Nuclear Information System (INIS)

    Ma, E.; Atzmon, M.; Bellon, P.; Trivedi, R.

    1998-01-01

    This volume compiles invited and contributed papers that were presented at Symposium B of the 1997 Materials Research Society Fall Meeting, Phase Transformations and Systems Driven Far From Equilibrium, which was held December 1--5, in Boston, Massachusetts. While this symposium followed the tradition of previous MRS symposia on the fundamental topic of phase transformations, this year the emphasis was on materials systems driven far from equilibrium. The central theme of the majority of the work presented is the understanding of the thermodynamics and kinetics of phase transformations, with significant coverage of metastable materials and externally forced transformations driven, for example, by energy beams or mechanical deformation. The papers are arranged in seven sections: solidification theory and experiments; nucleation; solid state transformations and microstructural evolution; beam-induced transformations; amorphous solids; interfacial and thin film transformations; and nanophases and mechanical alloying. One hundred three papers have been processed separately for inclusion on the data base

  18. Effects-Driven IT Development: Status 2004-2011

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2011-01-01

    that the desired effects can be specified and measured, though we have mixed experiences with ensuring that effects are measured. An effects hierarchy has been devised and appears suitable for working with effects at different levels of abstraction. A key challenge with which we still have insufficient experience...... the benefits of the deployed system. Effects-driven IT development aims to counter this risk by providing an instrument for managing IT projects through a sustained focus on the effects desired from the use of the IT system. A sustained focus on effects entails that the specification, realization......, and assessment of effects become central systems-development activities. In this chapter, we describe the six empirical projects we have conducted in our work on effects-driven IT development during the period 2004–2011 and we discuss the experiences gained so far. The empirical projects indicate...

  19. Test Driven Development of Scientific Models

    Science.gov (United States)

    Clune, Thomas L.

    2014-01-01

    Test-Driven Development (TDD), a software development process that promises many advantages for developer productivity and software reliability, has become widely accepted among professional software engineers. As the name suggests, TDD practitioners alternate between writing short automated tests and producing code that passes those tests. Although this overly simplified description will undoubtedly sound prohibitively burdensome to many uninitiated developers, the advent of powerful unit-testing frameworks greatly reduces the effort required to produce and routinely execute suites of tests. By testimony, many developers find TDD to be addicting after only a few days of exposure, and find it unthinkable to return to previous practices.After a brief overview of the TDD process and my experience in applying the methodology for development activities at Goddard, I will delve more deeply into some of the challenges that are posed by numerical and scientific software as well as tools and implementation approaches that should address those challenges.

  20. Laser-Driven Mini-Thrusters

    International Nuclear Information System (INIS)

    Sterling, Enrique; Lin Jun; Sinko, John; Kodgis, Lisa; Porter, Simon; Pakhomov, Andrew V.; Larson, C. William; Mead, Franklin B. Jr.

    2006-01-01

    Laser-driven mini-thrusters were studied using Delrin registered and PVC (Delrin registered is a registered trademark of DuPont) as propellants. TEA CO2 laser (λ = 10.6 μm) was used as a driving laser. Coupling coefficients were deduced from two independent techniques: force-time curves measured with a piezoelectric sensor and ballistic pendulum. Time-resolved ICCD images of the expanding plasma and combustion products were analyzed in order to determine the main process that generates the thrust. The measurements were also performed in a nitrogen atmosphere in order to test the combustion effects on thrust. A pinhole transmission experiment was performed for the study of the cut-off time when the ablation/air breakdown plasma becomes opaque to the incoming laser pulse

  1. Laser-Driven Mini-Thrusters

    Science.gov (United States)

    Sterling, Enrique; Lin, Jun; Sinko, John; Kodgis, Lisa; Porter, Simon; Pakhomov, Andrew V.; Larson, C. William; Mead, Franklin B.

    2006-05-01

    Laser-driven mini-thrusters were studied using Delrin® and PVC (Delrin® is a registered trademark of DuPont) as propellants. TEA CO2 laser (λ = 10.6 μm) was used as a driving laser. Coupling coefficients were deduced from two independent techniques: force-time curves measured with a piezoelectric sensor and ballistic pendulum. Time-resolved ICCD images of the expanding plasma and combustion products were analyzed in order to determine the main process that generates the thrust. The measurements were also performed in a nitrogen atmosphere in order to test the combustion effects on thrust. A pinhole transmission experiment was performed for the study of the cut-off time when the ablation/air breakdown plasma becomes opaque to the incoming laser pulse.

  2. Kaehler-driven tribrid inflation

    International Nuclear Information System (INIS)

    Antusch, Stefan; Nolde, David

    2012-01-01

    We discuss a new class of tribrid inflation models in supergravity, where the shape of the inflaton potential is dominated by effects from the Kaehler potential. Tribrid inflation is a variant of hybrid inflation which is particularly suited for connecting inflation with particle physics, since the inflaton can be a D-flat combination of charged fields from the matter sector. In models of tribrid inflation studied so far, the inflaton potential was dominated by either loop corrections or by mixing effects with the waterfall field (as in 'pseudosmooth' tribrid inflation). Here we investigate the third possibility, namely that tribrid inflation is dominantly driven by effects from higher-dimensional operators of the Kaehler potential. We specify for which superpotential parameters the new regime is realized and show how it can be experimentally distinguished from the other two (loop-driven and p seudosmooth ) regimes

  3. Investigation of Current Driven Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Agerkvist, Finn T.; Knott, Arnold

    2015-01-01

    Current driven loudspeakers have previously been investigated but the literature is limited and the advantages and disadvantages are yet to be fully identified. This paper makes use of a non-linear loudspeaker model to analyse loudspeakers with distinct non-linear characteristics under voltage an......” woofer where a copper ring in the pole piece has not been implemented to compensate for eddy currents. However the drive method seems to be irrelevant for a 5” woofer where the compliance, force factor as well as the voice coil inductance has been optimized for linearity.......Current driven loudspeakers have previously been investigated but the literature is limited and the advantages and disadvantages are yet to be fully identified. This paper makes use of a non-linear loudspeaker model to analyse loudspeakers with distinct non-linear characteristics under voltage...

  4. Effects-Driven IT Development

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2011-01-01

    For customers information technology (IT) is a means to an end. This tight association between IT systems and their use is, however, often absent during their development and implementation, resulting in systems that may fail to produce desired ends. Effects-driven IT development aims to avoid...... change that realize the specified effects, and (c) measuring the absence or presence of the specified effects during pilot use of the system while also remaining alert to the emergence of beneficial but hitherto unspecified effects. In this paper we explore effects-driven IT development and discuss...... the possibilities and challenges involved in making it an instrument for managing IT projects. Two main challenges are that effects must be measured while development is still ongoing, making pilot implementations a central activity, and that vendor and customer must extend their collaboration, particularly...

  5. System and safety studies of accelerator driven transmutation. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, W.; Wallenius, J.; Tucek, K.; Eriksson, Marcus; Carlsson, Johan; Seltborg, P.; Cetnar, J.; Chakarova, R.; Jollkonen, Mikael; Westlen, D. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Nuclear and Reactor Physics

    2003-06-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the Dept. of Nuclear and Reactor Physics has been largely determined by the program of the European projects of the the 5th Framework Programme. In particular: a) ADS core design and development of advanced nuclear fuel optimized for high transmutation rates and good safety features. This activity includes computer modeling of nuclear fuel production. Three different ADS-core concept are being investigated: Conceptual design of Pb-Bi cooled core with nitride fuel - so called Sing-Sing Core; Pb-Bi cooled core with oxide fuel; Gas cooled core with oxide fuel - both designs investigated for the European Project PDS-XADS; b) analysis of ADS-dynamics and assessment of major reactivity feedbacks; c) emergency heat removal from ADS; d) participation in ADS experiments including 1 MW spallation target manufacturing, subcritical experiments MUSE, YALINA subcritical experiment in Minsk and designing of the subcritical experiment SAD in Dubna; e) material studies for ADS, in particular theoretical and simulation studies of radiation damage in high neutron (or proton) fluxes; f) computer code and nuclear data development relevant for simulation and optimization of ADS, special efforts were put in the frame of the European Project PDS-XADS to perform sensitivity studies of the different nuclear data libraries; g) studies of transmutation potential of critical reactors in particular High Temp Gas Cooled Reactor. Most important finding and conclusions from our studies: A strong positive void coefficient was found for lead/bismuth cooled cores. This considerable void effect is attributed to a high fraction of americium (60%) in the fuel. It was found that void reactivity insertion rates increases with P/D; in response to the beam overpower accident the Pb/Bi-cooled core featured the twice longer grace time compared to the sodium-cooled core; an important safety issue is the high void worth that could

  6. Security and policy driven computing

    CERN Document Server

    Liu, Lei

    2010-01-01

    Security and Policy Driven Computing covers recent advances in security, storage, parallelization, and computing as well as applications. The author incorporates a wealth of analysis, including studies on intrusion detection and key management, computer storage policy, and transactional management.The book first describes multiple variables and index structure derivation for high dimensional data distribution and applies numeric methods to proposed search methods. It also focuses on discovering relations, logic, and knowledge for policy management. To manage performance, the text discusses con

  7. Monte Carlo simulation of a TRIGA source driven core configuration: Preliminary results

    International Nuclear Information System (INIS)

    Burgio, N.; Ciavola, C.; Santagata, A.

    2002-01-01

    The different core configurations with a k eff ranging from 0.93 to 0.98, and their response when driven by a pulsed neutron source were simulated with MCNP4C3 (Los Alamos - Monte Carlo N Particles). Simulation results could be considered both as preliminary check for nuclear data and a conceptual design for 'source jerk' experiments on the frame of TRIGA Accelerator Driven Experiment (TRADE) on the reactor facility of Casaccia research center. (author)

  8. Production of dissociated hydrogen gas by electro-magnetically driven shock

    International Nuclear Information System (INIS)

    Kondo, Kotaro; Moriyama, Takao; Hasegawa, Jun; Horioka, Kazuhiko; Oguri, Yoshiyuki

    2013-01-01

    Evaluation of ion stopping power which has a dependence on target temperature and density is an essential issue for heavy-ion-driven high energy density experiment. We focus on experimentally unknown dissociated hydrogen atoms as target for stopping power measurement. The precise measurement of shock wave velocity is required because the dissociated gas is produced by electro-magnetically driven shock. For beam-dissociated hydrogen gas interaction experiment, shock velocity measurement using laser refraction is proposed. (author)

  9. Temporal Data-Driven Sleep Scheduling and Spatial Data-Driven Anomaly Detection for Clustered Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Gang Li

    2016-09-01

    Full Text Available The spatial–temporal correlation is an important feature of sensor data in wireless sensor networks (WSNs. Most of the existing works based on the spatial–temporal correlation can be divided into two parts: redundancy reduction and anomaly detection. These two parts are pursued separately in existing works. In this work, the combination of temporal data-driven sleep scheduling (TDSS and spatial data-driven anomaly detection is proposed, where TDSS can reduce data redundancy. The TDSS model is inspired by transmission control protocol (TCP congestion control. Based on long and linear cluster structure in the tunnel monitoring system, cooperative TDSS and spatial data-driven anomaly detection are then proposed. To realize synchronous acquisition in the same ring for analyzing the situation of every ring, TDSS is implemented in a cooperative way in the cluster. To keep the precision of sensor data, spatial data-driven anomaly detection based on the spatial correlation and Kriging method is realized to generate an anomaly indicator. The experiment results show that cooperative TDSS can realize non-uniform sensing effectively to reduce the energy consumption. In addition, spatial data-driven anomaly detection is quite significant for maintaining and improving the precision of sensor data.

  10. Data-Driven Design: Learning from Student Experiences and Behaviors

    Science.gov (United States)

    Horodyskyj, L.; Mead, C.; Buxner, S.; Semken, S. C.; Anbar, A. D.

    2015-12-01

    Good instructors know that lessons and courses change over time. Limitations in time and data often prevent instructors from making changes that will most benefit their students. For example, in traditional in-person classrooms an instructor may only have access to the final product of a student's thought processes (such as a term paper, homework assignment, or exam). The thought processes that lead to a given answer are opaque to the instructor, making future modifications to course content an exercise in trial-and-error and instinct. Modern online intelligent tutoring systems can provide insight into a student's behavior, providing transparency to a previously opaque process and providing the instructor with better information for course modification. Habitable Worlds is an introductory level online-only astrobiology lab course that has been offered at Arizona State University since Fall 2011. The course is built and offered through an intelligent tutoring system, Smart Sparrow's Adaptive eLearning Platform, which provides in-depth analytics that allow the instructor to investigate detailed student behavior, from time spent on question to number of attempts to patterns of answers. We will detail the process we employ of informed modification of course content, including time and trial comparisons between semesters, analysis of submitted answers, analysis of alternative learning pathways taken, and A/B testing.

  11. Epigenetic mechanisms in experience-driven memory formation and behavior

    Science.gov (United States)

    Puckett, Rosemary E; Lubin, Farah D

    2011-01-01

    Epigenetic mechanisms have long been associated with the regulation of gene-expression changes accompanying normal neuronal development and cellular differentiation; however, until recently these mechanisms were believed to be statically quiet in the adult brain. Behavioral neuroscientists have now begun to investigate these epigenetic mechanisms as potential regulators of gene-transcription changes in the CNS subserving synaptic plasticity and long-term memory (LTM) formation. Experimental evidence from learning and memory animal models has demonstrated that active chromatin remodeling occurs in terminally differentiated postmitotic neurons, suggesting that these molecular processes are indeed intimately involved in several stages of LTM formation, including consolidation, reconsolidation and extinction. Such chromatin modifications include the phosphorylation, acetylation and methylation of histone proteins and the methylation of associated DNA to subsequently affect transcriptional gene readout triggered by learning. The present article examines how such learning-induced epigenetic changes contribute to LTM formation and influence behavior. In particular, this article is a survey of the specific epigenetic mechanisms that have been demonstrated to regulate gene expression for both transcription factors and growth factors in the CNS, which are critical for LTM formation and storage, as well as how aberrant epigenetic processing can contribute to psychological states such as schizophrenia and drug addiction. Together, the findings highlighted in this article support a novel role for epigenetic mechanisms in the adult CNS serving as potential key molecular regulators of gene-transcription changes necessary for LTM formation and adult behavior. PMID:22126252

  12. An Applied Project-Driven Approach to Undergraduate Research Experiences

    Science.gov (United States)

    Karls, Michael A.

    2017-01-01

    In this paper I will outline the process I have developed for conducting applied mathematics research with undergraduates and give some examples of the projects we have worked on. Several of these projects have led to refereed publications that could be used to illustrate topics taught in the undergraduate curriculum.

  13. The cross section sensitivity of the minor actinides on a lead-bismuth cooled accelerator-driven burner system

    International Nuclear Information System (INIS)

    Gil, Choong-Sup; Kim, Jung-Do; Chang, Jonghwa

    2002-01-01

    In order to validate the detailed sensitivity of each minor actinide datum in ENDF/B-VI Release 6, JEF-2.2 and JENDL-3.2 on an accelerator-driven minor actinide burner benchmark system, a lead-bismuth cooled sub-critical system was analyzed. The impacts on the system by the ten minor actinides were compared. The k eff values and reaction rates were calculated by exchanging the data sets of each minor actinide from ENDF/B-VI.6 to JEF-2.2 or JENDL-3.2. At the equilibrium core, the k eff differences from ENDF/B-VI.6 by the ten minor actinides can cause more than 5,500 pcm for JEF-2.2 and 3,500 pcm for JENDL-3.2. The fission reaction rates of 242m Am and 243 Cm with ENDF/B-VI.6 show differences of more than 15% from those with JEF-2.2 and JENDL-3.2. 241 Am, 243 Am and 245 Cm in JEF-2.2 and americium isotope data and 245 Cm in JENDL-3.2 are sensitive to the fission spectrum. (author)

  14. Segmentation-DrivenTomographic Reconstruction

    DEFF Research Database (Denmark)

    Kongskov, Rasmus Dalgas

    such that the segmentation subsequently can be carried out by use of a simple segmentation method, for instance just a thresholding method. We tested the advantages of going from a two-stage reconstruction method to a one stage segmentation-driven reconstruction method for the phase contrast tomography reconstruction......The tomographic reconstruction problem is concerned with creating a model of the interior of an object from some measured data, typically projections of the object. After reconstructing an object it is often desired to segment it, either automatically or manually. For computed tomography (CT...

  15. Data driven marketing for dummies

    CERN Document Server

    Semmelroth, David

    2013-01-01

    Embrace data and use it to sell and market your products Data is everywhere and it keeps growing and accumulating. Companies need to embrace big data and make it work harder to help them sell and market their products. Successful data analysis can help marketing professionals spot sales trends, develop smarter marketing campaigns, and accurately predict customer loyalty. Data Driven Marketing For Dummies helps companies use all the data at their disposal to make current customers more satisfied, reach new customers, and sell to their most important customer segments more efficiently. Identifyi

  16. Implementing Genome-Driven Oncology

    Science.gov (United States)

    Hyman, David M.; Taylor, Barry S.; Baselga, José

    2017-01-01

    Early successes in identifying and targeting individual oncogenic drivers, together with the increasing feasibility of sequencing tumor genomes, have brought forth the promise of genome-driven oncology care. As we expand the breadth and depth of genomic analyses, the biological and clinical complexity of its implementation will be unparalleled. Challenges include target credentialing and validation, implementing drug combinations, clinical trial designs, targeting tumor heterogeneity, and deploying technologies beyond DNA sequencing, among others. We review how contemporary approaches are tackling these challenges and will ultimately serve as an engine for biological discovery and increase our insight into cancer and its treatment. PMID:28187282

  17. Impact Forces from Tsunami-Driven Debris

    Science.gov (United States)

    Ko, H.; Cox, D. T.; Riggs, H.; Naito, C. J.; Kobayashi, M. H.; Piran Aghl, P.

    2012-12-01

    Debris driven by tsunami inundation flow has been known to be a significant threat to structures, yet we lack the constitutive equations necessary to predict debris impact force. The objective of this research project is to improve our understanding of, and predictive capabilities for, tsunami-driven debris impact forces on structures. Of special interest are shipping containers, which are virtually everywhere and which will float even when fully loaded. The forces from such debris hitting structures, for example evacuation shelters and critical port facilities such as fuel storage tanks, are currently not known. This research project focuses on the impact by flexible shipping containers on rigid columns and investigated using large-scale laboratory testing. Full-scale in-air collision experiments were conducted at Lehigh University with 20 ft shipping containers to experimentally quantify the nonlinear behavior of full scale shipping containers as they collide into structural elements. The results from the full scale experiments were used to calibrate computer models and used to design a series of simpler, 1:5 scale wave flume experiments at Oregon State University. Scaled in-air collision tests were conducted using 1:5 scale idealized containers to mimic the container behavior observed in the full scale tests and to provide a direct comparison to the hydraulic model tests. Two specimens were constructed using different materials (aluminum, acrylic) to vary the stiffness. The collision tests showed that at higher speeds, the collision became inelastic as the slope of maximum impact force/velocity decreased with increasing velocity. Hydraulic model tests were conducted using the 1:5 scaled shipping containers to measure the impact load by the containers on a rigid column. The column was instrumented with a load cell to measure impact forces, strain gages to measure the column deflection, and a video camera was used to provide the debris orientation and speed. The

  18. On Rank Driven Dynamical Systems

    Science.gov (United States)

    Veerman, J. J. P.; Prieto, F. J.

    2014-08-01

    We investigate a class of models related to the Bak-Sneppen (BS) model, initially proposed to study evolution. The BS model is extremely simple and yet captures some forms of "complex behavior" such as self-organized criticality that is often observed in physical and biological systems. In this model, random fitnesses in are associated to agents located at the vertices of a graph . Their fitnesses are ranked from worst (0) to best (1). At every time-step the agent with the worst fitness and some others with a priori given rank probabilities are replaced by new agents with random fitnesses. We consider two cases: The exogenous case where the new fitnesses are taken from an a priori fixed distribution, and the endogenous case where the new fitnesses are taken from the current distribution as it evolves. We approximate the dynamics by making a simplifying independence assumption. We use Order Statistics and Dynamical Systems to define a rank-driven dynamical system that approximates the evolution of the distribution of the fitnesses in these rank-driven models, as well as in the BS model. For this simplified model we can find the limiting marginal distribution as a function of the initial conditions. Agreement with experimental results of the BS model is excellent.

  19. Research coordination meeting of the coordinated research project on analytical and experimental benchmark analyses of accelerator driven systems. Working material

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    's overall objective is to make contributions towards the realization of a transmutation demonstration facility. The specific objective of the CRP is to improve the present understanding of the coupling of the ADS spallation source with the multiplicative sub-critical core. As outcome, the CRP aims at advancing the efforts under way in the Member States towards the proof of practicality for ADS based transmutation by providing an information exchange and collaborative research framework needed to ensure that the tools to perform detailed ADS calculations, namely from the high energy proton beam down to thermal neutron energies, are available. The CRP will address all major physics phenomena of the spallation source and its coupling to the sub-critical core. The participants will perform computational and experimental benchmark analyses using integrated calculation schemes and simulation methods. Apart from analytical benchmark exercises, the CRP will integrate some of the planned experimental demonstration projects of the coupling at power between a sub-critical core and a spallation source (e.g., YALINA Booster in Belarus and SAD at JINR, Dubna). The estimated duration of the CRP is 5 years. Following the establishment, during 2004, of the international CRP team by putting in place research agreements and contracts, and after convening this kick-off research RCM, the implementation plan of the CRP foresees three more RCMs (in 2007, 2008, and 2009, respectively), and the publication of the final report in 2010.

  20. Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.

    Science.gov (United States)

    Haasdijk, Evert; Bredeche, Nicolas; Eiben, A E

    2014-01-01

    Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-)adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability), and secondly they must competently perform user-specified tasks (usefulness). The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee) framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

  1. Combining environment-driven adaptation and task-driven optimisation in evolutionary robotics.

    Directory of Open Access Journals (Sweden)

    Evert Haasdijk

    Full Text Available Embodied evolutionary robotics is a sub-field of evolutionary robotics that employs evolutionary algorithms on the robotic hardware itself, during the operational period, i.e., in an on-line fashion. This enables robotic systems that continuously adapt, and are therefore capable of (re-adjusting themselves to previously unknown or dynamically changing conditions autonomously, without human oversight. This paper addresses one of the major challenges that such systems face, viz. that the robots must satisfy two sets of requirements. Firstly, they must continue to operate reliably in their environment (viability, and secondly they must competently perform user-specified tasks (usefulness. The solution we propose exploits the fact that evolutionary methods have two basic selection mechanisms-survivor selection and parent selection. This allows evolution to tackle the two sets of requirements separately: survivor selection is driven by the environment and parent selection is based on task-performance. This idea is elaborated in the Multi-Objective aNd open-Ended Evolution (monee framework, which we experimentally validate. Experiments with robotic swarms of 100 simulated e-pucks show that monee does indeed promote task-driven behaviour without compromising environmental adaptation. We also investigate an extension of the parent selection process with a 'market mechanism' that can ensure equitable distribution of effort over multiple tasks, a particularly pressing issue if the environment promotes specialisation in single tasks.

  2. User-driven sampling strategies in image exploitation

    Science.gov (United States)

    Harvey, Neal; Porter, Reid

    2013-12-01

    Visual analytics and interactive machine learning both try to leverage the complementary strengths of humans and machines to solve complex data exploitation tasks. These fields overlap most significantly when training is involved: the visualization or machine learning tool improves over time by exploiting observations of the human-computer interaction. This paper focuses on one aspect of the human-computer interaction that we call user-driven sampling strategies. Unlike relevance feedback and active learning sampling strategies, where the computer selects which data to label at each iteration, we investigate situations where the user selects which data is to be labeled at each iteration. User-driven sampling strategies can emerge in many visual analytics applications but they have not been fully developed in machine learning. User-driven sampling strategies suggest new theoretical and practical research questions for both visualization science and machine learning. In this paper we identify and quantify the potential benefits of these strategies in a practical image analysis application. We find user-driven sampling strategies can sometimes provide significant performance gains by steering tools towards local minima that have lower error than tools trained with all of the data. In preliminary experiments we find these performance gains are particularly pronounced when the user is experienced with the tool and application domain.

  3. Wonder-driven Entrepreneurship Teaching

    DEFF Research Database (Denmark)

    Hansen, Finn Thorbjørn; Herholdt-Lomholdt, Sine Maria

    Contemporary research on creativity, innovation and entrepreneurship have now for a decade or more been focusing on social constructive, pragmatic, socio-cultural and socio-material dimensions of creative and innovative processes and entrepreneurship (Bager et al. 2010, Brinkmann & Tangaard 2010......- and entrepreneurship processes. In this paper we want to continue in line with this new framework of meaning- and wonder-driven innovation by focusing on the possible educational consequences of such an approach. Our empirical departure is our three-year phenomenological action research project called ‘Wonder......-based Entrepreneurship Teaching in Professional bachelor Education’. Ten senior lecturers in nursing and pedagogy participated. The purpose was to investigate whether and how Socratic and philosophical dialogues and different forms of phenomenological and existential reflections upon one´s own professional assumptions...

  4. Customer-driven Product Development

    DEFF Research Database (Denmark)

    Sommer, Anita Friis

    2011-01-01

    look for new ways to gain competitive advantage. In competitive markets there is a tendency of shorter product life cycles, and thus a competitive factor is to keep at pace with the market or even driving the market by developing new products. This research study seeks to investigate Customer......Demand chain management is a research area of increasing attention. It is the undertaking of reacting to customer requirements through a responsive chain going from customers through a focal company towards raw material distributors. With faster growing markets and increasing competition, companies......-driven Product Development (CDPD) from a demand chain management perspective. CDPD is the counterpart to typical research and development processes, which has no direct customer involvement. The proposition is that letting customers initiate and participate in the product development process...

  5. Laser driven fusion fission hybrids

    International Nuclear Information System (INIS)

    Hansen, L.F.; Maniscalco, J.A.

    1977-11-01

    The role of the fusion-fission hybrid reactor (FFHR) as a fissile fuel and/or power producer is discussed. As long range options to supply the world energy needs, hybrid-fueled thermal-burner reactors are compared to liquid metal fast breeder reactors (LMFBR). A discussion of different fuel cycles (thorium, depleted uranium, and spent fuel) is presented in order to compare the energy multiplication, the production of fissile fuel, the laser efficiency and pellet gain requirements of the hybrid reactor. Lawrence Livermore Laboratory (LLL) has collaborated with Bechtel Corporation and with Westinghouse in two engineering design studies of laser fusion driven hybrid power plants. The hybrid designs which have resulted from these two studies are briefly described and analyzed by considering operational parameters, such as energy multiplication, power density, burn-up and plutonium production as a function time

  6. Multifunctionalities driven by ferroic domains

    Science.gov (United States)

    Yang, J. C.; Huang, Y. L.; He, Q.; Chu, Y. H.

    2014-08-01

    Considerable attention has been paid to ferroic systems in pursuit of advanced applications in past decades. Most recently, the emergence and development of multiferroics, which exhibit the coexistence of different ferroic natures, has offered a new route to create functionalities in the system. In this manuscript, we step from domain engineering to explore a roadmap for discovering intriguing phenomena and multifunctionalities driven by periodic domain patters. As-grown periodic domains, offering exotic order parameters, periodic local perturbations and the capability of tailoring local spin, charge, orbital and lattice degrees of freedom, are introduced as modeling templates for fundamental studies and novel applications. We discuss related significant findings on ferroic domain, nanoscopic domain walls, and conjunct heterostructures based on the well-organized domain patterns, and end with future prospects and challenges in the field.

  7. Heat-driven spin torques in antiferromagnets

    Science.gov (United States)

    Białek, Marcin; Bréchet, Sylvain; Ansermet, Jean-Philippe

    2018-04-01

    Heat-driven magnetization damping, which is a linear function of a temperature gradient, is predicted in antiferromagnets by considering the sublattice dynamics subjected to a heat-driven spin torque. This points to the possibility of achieving spin torque oscillator behavior. The model is based on the magnetic Seebeck effect acting on sublattices which are exchange coupled. The heat-driven spin torque is estimated and the feasibility of detecting this effect is discussed.

  8. Laser interferometry of radiation driven gas jets

    Science.gov (United States)

    Swanson, Kyle James; Ivanov, Vladimir; Mancini, Roberto; Mayes, Daniel C.

    2017-06-01

    In a series of experiments performed at the 1MA Zebra pulsed power accelerator of the Nevada Terawatt Facility nitrogen gas jets were driven with the broadband x-ray flux produced during the collapse of a wire-array z-pinch implosion. The wire arrays were comprised of 4 and 8, 10μm-thick gold wires and 17μm-thick nickel wires, 2cm and 3cm tall, and 0.3cm in diameter. They radiated 12kJ to 16kJ of x-ray energy, most of it in soft x-ray photons of less than 1keV of energy, in a time interval of 30ns. This x-ray flux was used to drive a nitrogen gas jet located at 0.8cm from the axis of the z-pinch radiation source and produced with a supersonic nozzle. The x-ray flux ionizes the nitrogen gas thus turning it into a photoionized plasma. We used laser interferometry to probe the ionization of the plasma. To this end, a Mach-Zehnder interferometer at the wavelength of 266 nm was set up to extract the atom number density profile of the gas jet just before the Zebra shot, and air-wedge interferometers at 266 and 532 nm were used to determine the electron number density of the plasma right during the Zebra shot. The ratio of electron to atom number densities gives the distribution of average ionization state of the plasma. A python code was developed to perform the image data processing, extract phase shift spatial maps, and obtain the atom and electron number densities via Abel inversion. Preliminary results from the experiment are promising and do show that a plasma has been created in the gas jet driven by the x-ray flux, thus demonstrating the feasibility of a new experimental platform to study photoionized plasmas in the laboratory. These plasmas are found in astrophysical scenarios including x-ray binaries, active galactic nuclei, and the accretion disks surrounding black holes1. This work was sponsored in part by DOE Office of Science Grant DE-SC0014451.1R. C. Mancini et al, Phys. Plasmas 16, 041001 (2009)

  9. Design Driven Testing Test Smarter, Not Harder

    CERN Document Server

    Stephens, M

    2010-01-01

    The groundbreaking book Design Driven Testing brings sanity back to the software development process by flipping around the concept of Test Driven Development (TDD) - restoring the concept of using testing to verify a design instead of pretending that unit tests are a replacement for design. Anyone who feels that TDD is "Too Damn Difficult" will appreciate this book. Design Driven Testing shows that, by combining a forward-thinking development process with cutting-edge automation, testing can be a finely targeted, business-driven, rewarding effort. In other words, you'll learn how to test

  10. How Evolution May Work Through Curiosity-Driven Developmental Process.

    Science.gov (United States)

    Oudeyer, Pierre-Yves; Smith, Linda B

    2016-04-01

    Infants' own activities create and actively select their learning experiences. Here we review recent models of embodied information seeking and curiosity-driven learning and show that these mechanisms have deep implications for development and evolution. We discuss how these mechanisms yield self-organized epigenesis with emergent ordered behavioral and cognitive developmental stages. We describe a robotic experiment that explored the hypothesis that progress in learning, in and for itself, generates intrinsic rewards: The robot learners probabilistically selected experiences according to their potential for reducing uncertainty. In these experiments, curiosity-driven learning led the robot learner to successively discover object affordances and vocal interaction with its peers. We explain how a learning curriculum adapted to the current constraints of the learning system automatically formed, constraining learning and shaping the developmental trajectory. The observed trajectories in the robot experiment share many properties with those in infant development, including a mixture of regularities and diversities in the developmental patterns. Finally, we argue that such emergent developmental structures can guide and constrain evolution, in particular with regard to the origins of language. Copyright © 2016 Cognitive Science Society, Inc.

  11. Scaling Laws for Unstable Interfaces Driven by Strong Shocks in Cylindrical Geometry

    International Nuclear Information System (INIS)

    Zhang, Q.; Graham, M.J.; Graham, M.J.

    1997-01-01

    The Richtmyer-Meshkov (RM) instability is an interfacial interface between two fluids of different densities driven by shock waves and plays an important role in the studies of inertial confinement fusion and of supernovas. So far, most of the studies are for RM unstable interfaces driven by weak or intermediate shocks in planar geometry. For experiments conducted at the Nova laser, the unstable material interface is accelerated by very strong shocks. In this Letter, we present scaling laws for the RM unstable interface driven by strong imploding and exploding shocks. copyright 1997 The American Physical Society

  12. Parametric instabilities in resonantly-driven Bose–Einstein condensates

    Science.gov (United States)

    Lellouch, S.; Goldman, N.

    2018-04-01

    Shaking optical lattices in a resonant manner offers an efficient and versatile method to devise artificial gauge fields and topological band structures for ultracold atomic gases. This was recently demonstrated through the experimental realization of the Harper–Hofstadter model, which combined optical superlattices and resonant time-modulations. Adding inter-particle interactions to these engineered band systems is expected to lead to strongly-correlated states with topological features, such as fractional Chern insulators. However, the interplay between interactions and external time-periodic drives typically triggers violent instabilities and uncontrollable heating, hence potentially ruling out the possibility of accessing such intriguing states of matter in experiments. In this work, we study the early-stage parametric instabilities that occur in systems of resonantly-driven Bose–Einstein condensates in optical lattices. We apply and extend an approach based on Bogoliubov theory (Lellouch et al 2017 Phys. Rev. X 7 021015) to a variety of resonantly-driven band models, from a simple shaken Wannier–Stark ladder to the more intriguing driven-induced Harper–Hofstadter model. In particular, we provide ab initio numerical and analytical predictions for the stability properties of these topical models. This work sheds light on general features that could guide current experiments to stable regimes of operation.

  13. Challenges and Limitations of Applying an Emotion-driven Design Approach on Elderly Users

    DEFF Research Database (Denmark)

    Andersen, Casper L.; Gudmundsson, Hjalte P.; Achiche, Sofiane

    2011-01-01

    a competitive advantage for companies. In this paper, challenges of applying an emotion-driven design approach applied on elderly people, in order to identify their user needs towards walking frames, are discussed. The discussion will be based on the experiences and results obtained from the case study...... related to the participants’ age and cognitive abilities. The challenges encountered are discussed and guidelines on what should be taken into account to facilitate an emotion-driven design approach for elderly people are proposed....

  14. Kinetic parameters for source driven systems

    International Nuclear Information System (INIS)

    Dulla, S.; Ravetto, P.; Carta, M.; D'Angelo, A.

    2006-01-01

    The definition of the characteristic kinetic parameters of a subcritical source-driven system constitutes an interesting problem in reactor physics with important consequences for practical applications. Consistent and physically meaningful values of the parameters allow to obtain accurate results from kinetic simulation tools and to correctly interpret kinetic experiments. For subcritical systems a preliminary problem arises for the adoption of a suitable weighting function to be used in the projection procedure to derive a point model. The present work illustrates a consistent factorization-projection procedure which leads to the definition of the kinetic parameters in a straightforward manner. The reactivity term is introduced coherently with the generalized perturbation theory applied to the source multiplication factor ks, which is thus given a physical role in the kinetic model. The effective prompt lifetime is introduced on the assumption that a neutron generation can be initiated by both the fission process and the source emission. Results are presented for simplified configurations to fully comprehend the physical features and for a more complicated highly decoupled system treated in transport theory. (authors)

  15. Kohn anomaly in phonon driven superconductors

    International Nuclear Information System (INIS)

    Das, M P; Chaudhury, R

    2014-01-01

    Anomalies often occur in the physical world. Sometimes quite unexpectedly anomalies may give rise to new insight to an unrecognized phenomenon. In this paper we shall discuss about Kohn anomaly in a conventional phonon-driven superconductor by using a microscopic approach. Recently Aynajian et al.'s experiment showed a striking feature; the energy of phonon at a particular wave-vector is almost exactly equal to twice the energy of the superconducting gap. Although the phonon mechanism of superconductivity is well known for many conventional superconductors, as has been noted by Scalapino, the new experimental results reveal a genuine puzzle. In our recent work we have presented a detailed theoretical analysis with the help of microscopic calculations to unravel this mystery. We probe this aspect of phonon behaviour from the properties of electronic polarizability function in the superconducting phase of a Fermi liquid metal, leading to the appearance of a Kohn singularity. We show the crossover to the standard Kohn anomaly of the normal phase for temperatures above the transition temperature. Our analysis provides a nearly complete explanation of this new experimentally discovered phenomenon. This report is a shorter version of our recent work in JPCM.

  16. Data-driven architectural production and operation

    NARCIS (Netherlands)

    Bier, H.H.; Mostafavi, S.

    2014-01-01

    Data-driven architectural production and operation as explored within Hyperbody rely heavily on system thinking implying that all parts of a system are to be understood in relation to each other. These relations are increasingly established bi-directionally so that data-driven architecture is not

  17. Resonances in a periodically driven bosonic system

    NARCIS (Netherlands)

    Quelle, Anton; de Morais Smith, Cristiane

    2017-01-01

    Periodically driven systems are a common topic in modern physics. In optical lattices specifically, driving is at the origin of many interesting phenomena. However, energy is not conserved in driven systems, and under periodic driving, heating of a system is a real concern. In an effort to better

  18. Role of compressibility on driven magnetic reconnection

    International Nuclear Information System (INIS)

    Sato, T.; Hayashi, T.; Watanabe, K.; Horiuchi, R.; Tanaka, M.; Sawairi, N.; Kusano, K.

    1991-08-01

    Whether it is induced by an ideal (current driven) instability or by an external force, plasma flow causes a change in the magnetic field configuration and often gives rise to a current intensification locally, thereby a fast driven reconnection being driven there. Many dramatic phenomena in magnetically confined plasmas such as magnetospheric substorms, solar flares, MHD self-organization and tokamak sawtooth crash, may be attributed to this fast driven reconnection. Using a fourth order MHD simulation code it is confirmed that compressibility of the plasma plays a crucial role in leading to a fast (MHD time scale) driven reconnection. This indicates that the incompressible representation is not always applicable to the study of a global dynamical behavior of a magnetically confined plasma. (author)

  19. Transmutation and accelerator driven systems

    International Nuclear Information System (INIS)

    Shapira, J.P.

    2001-01-01

    Full text: Today, countries who are presently involved in nuclear energy are facing many challenges to maintain this option open for the next few decades. Among them, management of nuclear wastes produced in nuclear reactors and in fuel cycle operations has become a very strong environmental issue among the public. In most countries with sizeable commercial nuclear programs, deep geological disposal of ultimate highly active and long-lived nuclear wastes is considered as the reference long-term management scheme. But, many questions arise on the possibility to demonstrate that such wastes can be dealt in such a way as to protect the future generations and the environment. The characteristics of nuclear wastes, the various back end policies concerning spent fuels and the nuclear wastes long-term management options will be first described. Then recent proposals, based on transmutation, especially those using accelerator driven systems (ADS) and/or thorium will be presented. Finally, the possibility for the nuclear physics community to play a part in alleviating the nuclear wastes burden will be pointed out. (author)

  20. Data-driven methods towards learning the highly nonlinear inverse kinematics of tendon-driven surgical manipulators.

    Science.gov (United States)

    Xu, Wenjun; Chen, Jie; Lau, Henry Y K; Ren, Hongliang

    2017-09-01

    Accurate motion control of flexible surgical manipulators is crucial in tissue manipulation tasks. The tendon-driven serpentine manipulator (TSM) is one of the most widely adopted flexible mechanisms in minimally invasive surgery because of its enhanced maneuverability in torturous environments. TSM, however, exhibits high nonlinearities and conventional analytical kinematics model is insufficient to achieve high accuracy. To account for the system nonlinearities, we applied a data driven approach to encode the system inverse kinematics. Three regression methods: extreme learning machine (ELM), Gaussian mixture regression (GMR) and K-nearest neighbors regression (KNNR) were implemented to learn a nonlinear mapping from the robot 3D position states to the control inputs. The performance of the three algorithms was evaluated both in simulation and physical trajectory tracking experiments. KNNR performed the best in the tracking experiments, with the lowest RMSE of 2.1275 mm. The proposed inverse kinematics learning methods provide an alternative and efficient way to accurately model the tendon driven flexible manipulator. Copyright © 2016 John Wiley & Sons, Ltd.

  1. Evaluation of respondent-driven sampling.

    Science.gov (United States)

    McCreesh, Nicky; Frost, Simon D W; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda N; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

    2012-01-01

    Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total population data. Total population data on age, tribe, religion, socioeconomic status, sexual activity, and HIV status were available on a population of 2402 male household heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, using current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). We recruited 927 household heads. Full and small RDS samples were largely representative of the total population, but both samples underrepresented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven sampling statistical inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven sampling bootstrap 95% confidence intervals included the population proportion. Respondent-driven sampling produced a generally representative sample of this well-connected nonhidden population. However, current respondent-driven sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience sampling method, and caution is required

  2. Evaluation of Respondent-Driven Sampling

    Science.gov (United States)

    McCreesh, Nicky; Frost, Simon; Seeley, Janet; Katongole, Joseph; Tarsh, Matilda Ndagire; Ndunguse, Richard; Jichi, Fatima; Lunel, Natasha L; Maher, Dermot; Johnston, Lisa G; Sonnenberg, Pam; Copas, Andrew J; Hayes, Richard J; White, Richard G

    2012-01-01

    Background Respondent-driven sampling is a novel variant of link-tracing sampling for estimating the characteristics of hard-to-reach groups, such as HIV prevalence in sex-workers. Despite its use by leading health organizations, the performance of this method in realistic situations is still largely unknown. We evaluated respondent-driven sampling by comparing estimates from a respondent-driven sampling survey with total-population data. Methods Total-population data on age, tribe, religion, socioeconomic status, sexual activity and HIV status were available on a population of 2402 male household-heads from an open cohort in rural Uganda. A respondent-driven sampling (RDS) survey was carried out in this population, employing current methods of sampling (RDS sample) and statistical inference (RDS estimates). Analyses were carried out for the full RDS sample and then repeated for the first 250 recruits (small sample). Results We recruited 927 household-heads. Full and small RDS samples were largely representative of the total population, but both samples under-represented men who were younger, of higher socioeconomic status, and with unknown sexual activity and HIV status. Respondent-driven-sampling statistical-inference methods failed to reduce these biases. Only 31%-37% (depending on method and sample size) of RDS estimates were closer to the true population proportions than the RDS sample proportions. Only 50%-74% of respondent-driven-sampling bootstrap 95% confidence intervals included the population proportion. Conclusions Respondent-driven sampling produced a generally representative sample of this well-connected non-hidden population. However, current respondent-driven-sampling inference methods failed to reduce bias when it occurred. Whether the data required to remove bias and measure precision can be collected in a respondent-driven sampling survey is unresolved. Respondent-driven sampling should be regarded as a (potentially superior) form of convenience

  3. Non-inductively driven currents in JET

    International Nuclear Information System (INIS)

    Challis, C.D.; Cordey, J.G.; Hamnen, H.; Stubberfield, P.M.; Christiansen, J.P.; Lazzaro, E.; Muir, D.G.; Stork, D.; Thompson, E.

    1989-01-01

    Neutral beam heating data from JET have been analysed in detail to determine what proportion of the current is driven non-inductively. It is found that in low density limiter discharges, currents of the order of 0.5 MA are driven, while in H-mode plasmas currents of the order of 0.7 MA are measured. These measured currents are found to be in reasonable agreement with theoretical predictions based on neoclassical models. In low density plasmas the beam driven current is large while the neoclassical bootstrap current dominates H-mode plasmas. (author). 19 refs, 11 figs

  4. Disentangling Competition Among Platform Driven Strategic Groups

    DEFF Research Database (Denmark)

    Kazan, Erol; Tan, Chee-Wee; Lim, Eric

    2015-01-01

    In platform-driven markets, competitive advantage is derived from superior platform design and configurations. For this reason, platform owners strive to create unique and inimitable platform configurals to maintain and extend their competitiveness within network economies. To disentangle firm...... competition within platform-driven markets, we opted for the UK mobile payment market as our empirical setting. By embracing the theoretical lens of strategic groups and digital platforms, this study supplements prior research by deriving a taxonomy of platform-driven strategic groups that is grounded...

  5. On fusion driven systems (FDS) for transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Aagren, O (Uppsala Univ., Aangstroem laboratory, div. of electricity, Uppsala (Sweden)); Moiseenko, V.E. (Inst. of Plasma Physics, National Science Center, Kharkov Inst. of Physics and Technology, Kharkov (Ukraine)); Noack, K. (Forschungszentrum Dresden-Rossendorf (Germany))

    2008-10-15

    This report gives a brief description of ongoing activities on fusion driven systems (FDS) for transmutation of the long-lived radioactive isotopes in the spent nuclear waste from fission reactors. Driven subcritical systems appears to be the only option for efficient minor actinide burning. Driven systems offer a possibility to increase reactor safety margins. A comparatively simple fusion device could be sufficient for a fusion-fission machine, and transmutation may become the first industrial application of fusion. Some alternative schemes to create strong fusion neutron fluxes are presented

  6. On fusion driven systems (FDS) for transmutation

    International Nuclear Information System (INIS)

    Aagren, O; Moiseenko, V.E.; Noack, K.

    2008-10-01

    This report gives a brief description of ongoing activities on fusion driven systems (FDS) for transmutation of the long-lived radioactive isotopes in the spent nuclear waste from fission reactors. Driven subcritical systems appears to be the only option for efficient minor actinide burning. Driven systems offer a possibility to increase reactor safety margins. A comparatively simple fusion device could be sufficient for a fusion-fission machine, and transmutation may become the first industrial application of fusion. Some alternative schemes to create strong fusion neutron fluxes are presented

  7. Emotion-driven interactive storytelling

    OpenAIRE

    Zhao, Huiwen

    2012-01-01

    Interactive storytelling has attracted plenty of research interest in recent years. Most current interactive storytelling systems follow a goal-oriented approach to story representation, i.e. the user is engaged with the story through fulfilling a number of goals rather than empathising with the characters and experiencing anenriched emotional experience (Pizzi and Cavazza 2007). This fails to satisfy potential users who are oriented to traditional media, such as movies (Louchart et al. 2008)...

  8. A Model-Driven Development Method for Management Information Systems

    Science.gov (United States)

    Mizuno, Tomoki; Matsumoto, Keinosuke; Mori, Naoki

    Traditionally, a Management Information System (MIS) has been developed without using formal methods. By the informal methods, the MIS is developed on its lifecycle without having any models. It causes many problems such as lack of the reliability of system design specifications. In order to overcome these problems, a model theory approach was proposed. The approach is based on an idea that a system can be modeled by automata and set theory. However, it is very difficult to generate automata of the system to be developed right from the start. On the other hand, there is a model-driven development method that can flexibly correspond to changes of business logics or implementing technologies. In the model-driven development, a system is modeled using a modeling language such as UML. This paper proposes a new development method for management information systems applying the model-driven development method to a component of the model theory approach. The experiment has shown that a reduced amount of efforts is more than 30% of all the efforts.

  9. A Study on a Microwave-Driven Smart Material Actuator

    Science.gov (United States)

    Choi, Sang H.; Chu, Sang-Hyon; Kwak, M.; Cutler, A. D.

    2001-01-01

    NASA s Next Generation Space Telescope (NGST) has a large deployable, fragmented optical surface (greater than or = 2 8 m in diameter) that requires autonomous correction of deployment misalignments and thermal effects. Its high and stringent resolution requirement imposes a great deal of challenge for optical correction. The threshold value for optical correction is dictated by lambda/20 (30 nm for NGST optics). Control of an adaptive optics array consisting of a large number of optical elements and smart material actuators is so complex that power distribution for activation and control of actuators must be done by other than hard-wired circuitry. The concept of microwave-driven smart actuators is envisioned as the best option to alleviate the complexity associated with hard-wiring. A microwave-driven actuator was studied to realize such a concept for future applications. Piezoelectric material was used as an actuator that shows dimensional change with high electric field. The actuators were coupled with microwave rectenna and tested to correlate the coupling effect of electromagnetic wave. In experiments, a 3x3 rectenna patch array generated more than 50 volts which is a threshold voltage for 30-nm displacement of a single piezoelectric material. Overall, the test results indicate that the microwave-driven actuator concept can be adopted for NGST applications.

  10. An experimental platform for pulsed-power driven magnetic reconnection

    Science.gov (United States)

    Hare, J. D.; Suttle, L. G.; Lebedev, S. V.; Loureiro, N. F.; Ciardi, A.; Chittenden, J. P.; Clayson, T.; Eardley, S. J.; Garcia, C.; Halliday, J. W. D.; Robinson, T.; Smith, R. A.; Stuart, N.; Suzuki-Vidal, F.; Tubman, E. R.

    2018-05-01

    We describe a versatile pulsed-power driven platform for magnetic reconnection experiments, based on the exploding wire arrays driven in parallel [Suttle et al., Phys. Rev. Lett. 116, 225001 (2016)]. This platform produces inherently magnetised plasma flows for the duration of the generator current pulse (250 ns), resulting in a long-lasting reconnection layer. The layer exists for long enough to allow the evolution of complex processes such as plasmoid formation and movement to be diagnosed by a suite of high spatial and temporal resolution laser-based diagnostics. We can access a wide range of magnetic reconnection regimes by changing the wire material or moving the electrodes inside the wire arrays. We present results with aluminium and carbon wires, in which the parameters of the inflows and the layer that forms are significantly different. By moving the electrodes inside the wire arrays, we change how strongly the inflows are driven. This enables us to study both symmetric reconnection in a range of different regimes and asymmetric reconnection.

  11. Modelling Laccoliths: Fluid-Driven Fracturing in the Lab

    Science.gov (United States)

    Ball, T. V.; Neufeld, J. A.

    2017-12-01

    Current modelling of the formation of laccoliths neglects the necessity to fracture rock layers for propagation to occur [1]. In magmatic intrusions at depth the idea of fracture toughness is used to characterise fracturing, however an analogue for near surface intrusions has yet to be explored [2]. We propose an analytical model for laccolith emplacement that accounts for the energy required to fracture at the tip of an intrusion. For realistic physical parameters we find that a lag region exists between the fluid magma front and the crack tip where large negative pressures in the tip cause volatiles to exsolve from the magma. Crucially, the dynamics of this tip region controls the spreading due to the competition between viscous forces and fracture energy. We conduct a series of complementary experiments to investigate fluid-driven fracturing of adhered layers and confirm the existence of two regimes: viscosity dominant spreading, controlled by the pressure in the lag region, and fracture energy dominant spreading, controlled by the energy required to fracture layers. Our experiments provide the first observations, and evolution, of a vapour tip. These experiments and our simplified model provide insight into the key physical processes in near surface magmatic intrusions with applications to fluid-driven fracturing more generally. Michaut J. Geophys. Res. 116(B5), B05205. Bunger & Cruden J. Geophys. Res. 116(B2), B02203.

  12. Z-petawatt driven ion beam radiography development.

    Energy Technology Data Exchange (ETDEWEB)

    Schollmeier, Marius; Geissel, Matthias; Rambo, Patrick K.; Schwarz, Jens; Sefkow, Adam B.

    2013-09-01

    Laser-driven proton radiography provides electromagnetic field mapping with high spatiotemporal resolution, and has been applied to many laser-driven High Energy Density Physics (HEDP) experiments. Our report addresses key questions about the feasibility of ion radiography at the Z-Accelerator (%E2%80%9CZ%E2%80%9D), concerning laser configuration, hardware, and radiation background. Charged particle tracking revealed that radiography at Z requires GeV scale protons, which is out of reach for existing and near-future laser systems. However, it might be possible to perform proton deflectometry to detect magnetic flux compression in the fringe field region of a magnetized liner inertial fusion experiment. Experiments with the Z-Petawatt laser to enhance proton yield and energy showed an unexpected scaling with target thickness. Full-scale, 3D radiation-hydrodynamics simulations, coupled to fully explicit and kinetic 2D particle-in-cell simulations running for over 10 ps, explain the scaling by a complex interplay of laser prepulse, preplasma, and ps-scale temporal rising edge of the laser.

  13. Perceived Effectiveness of Community-driven Development ...

    African Journals Online (AJOL)

    Perceived Effectiveness of Community-driven Development Approach of Community and Social ... African Journal of Sustainable Development ... that CSDP in Oyo state be scaled up and the CDD approach be adopted for rural development.

  14. Examples of Entropy-driven Ordering

    Indian Academy of Sciences (India)

    driven Ordering. Orientational ordering of long objects. Entropy of sliding increases. Freezing in hard-sphere systems. Vibrational entropy increases. Phase separation in hard-sphere binary mixtures with disparate sizes. More room for smaller ...

  15. Test-driven development with Django

    CERN Document Server

    Harvey, Kevin

    2015-01-01

    This book is for Django developers with little or no knowledge of test-driven development or testing in general. Familiarity with the command line, setting up a Python virtual environment, and starting a Django project are assumed.

  16. Distributed simulation a model driven engineering approach

    CERN Document Server

    Topçu, Okan; Oğuztüzün, Halit; Yilmaz, Levent

    2016-01-01

    Backed by substantive case studies, the novel approach to software engineering for distributed simulation outlined in this text demonstrates the potent synergies between model-driven techniques, simulation, intelligent agents, and computer systems development.

  17. Automated Testing of Event-Driven Applications

    DEFF Research Database (Denmark)

    Jensen, Casper Svenning

    may be tested by selecting an interesting input (i.e. a sequence of events), and deciding if a failure occurs when the selected input is applied to the event-driven application under test. Automated testing promises to reduce the workload for developers by automatically selecting interesting inputs...... and detect failures. However, it is non-trivial to conduct automated testing of event-driven applications because of, for example, infinite input spaces and the absence of specifications of correct application behavior. In this PhD dissertation, we identify a number of specific challenges when conducting...... automated testing of event-driven applications, and we present novel techniques for solving these challenges. First, we present an algorithm for stateless model-checking of event-driven applications with partial-order reduction, and we show how this algorithm may be used to systematically test web...

  18. Data-Driven Problems in Elasticity

    Science.gov (United States)

    Conti, S.; Müller, S.; Ortiz, M.

    2018-01-01

    We consider a new class of problems in elasticity, referred to as Data-Driven problems, defined on the space of strain-stress field pairs, or phase space. The problem consists of minimizing the distance between a given material data set and the subspace of compatible strain fields and stress fields in equilibrium. We find that the classical solutions are recovered in the case of linear elasticity. We identify conditions for convergence of Data-Driven solutions corresponding to sequences of approximating material data sets. Specialization to constant material data set sequences in turn establishes an appropriate notion of relaxation. We find that relaxation within this Data-Driven framework is fundamentally different from the classical relaxation of energy functions. For instance, we show that in the Data-Driven framework the relaxation of a bistable material leads to material data sets that are not graphs.

  19. Applications of laser-driven particle acceleration

    CERN Document Server

    Parodi, Katia; Schreiber, Jorg

    2018-01-01

    The first book of its kind to highlight the unique capabilities of laser-driven acceleration and its diverse potential, Applications of Laser-Driven Particle Acceleration presents the basic understanding of acceleration concepts and envisioned prospects for selected applications. As the main focus, this new book explores exciting and diverse application possibilities, with emphasis on those uniquely enabled by the laser driver that can also be meaningful and realistic for potential users. A key aim of the book is to inform multiple, interdisciplinary research communities of the new possibilities available and to inspire them to engage with laser-driven acceleration, further motivating and advancing this developing field. Material is presented in a thorough yet accessible manner, making it a valuable reference text for general scientific and engineering researchers who are not necessarily subject matter experts. Applications of Laser-Driven Particle Acceleration is edited by Professors Paul R. Bolton, Katia ...

  20. Leidenfrost Driven Waste-Water Separator

    Data.gov (United States)

    National Aeronautics and Space Administration — A Leidenfrost Driven Waste-Water Separator (LDS) is proposed in response to TA 6.1: Environmental Control and Life Support Systems and Habitation Systems. The LDS...

  1. Summary report : working group 5 on 'electron beam-driven plasma and structure based acceleration concepts'

    International Nuclear Information System (INIS)

    Conde, M. E.; Katsouleas, T.

    2000-01-01

    The talks presented and the work performed on electron beam-driven accelerators in plasmas and structures are summarized. Highlights of the working group include new experimental results from the E-157 Plasma Wakefield Experiment, the E-150 Plasma Lens Experiment and the Argonne Dielectric Structure Wakefield experiments. The presentations inspired discussion and analysis of three working topics: electron hose instability, ion channel lasers and the plasma afterburner

  2. High explosive driven plasma opening switches

    International Nuclear Information System (INIS)

    Greene, A.E.; Bowers, R.L.; Brownell, J.H.; Goforth, J.H.; Oliphant, T.A.; Weiss, D.L.

    1983-01-01

    A joint theoretical and experimental effort is underway to understand and improve upon the performance of high explosive driven plasma opening switches such as those first described by Pavlovskii et al. We have modeled these switches in both planar and cylindrical geometry using a one dimensional Lagrangian MHD code. This one-dimensional analysis is now essentially complete. It has shown that simple, one-dimensional, compression of the current-carrying channel can explain the observed resistance increases during the time of flight of the HE detonation products. Our calculations imply that ionization plays an important role as an energy sink and the performance of these switches might be improved by a judicious choice of gases. We also predict improved performance by lowering the pressure in the plasma channel. The bulk of our experimental effort to date has been with planar switches. We have worked with current densities of 0.25 to 0.4 MA/cm and have observed resistance increases of 40 to 60 mΩ. Significant resistance increases are observed later than the time of flight of the HE detonation products. We suggest that these resistance increases are due to mixing between the hot plasma and the relatively cooler detonation products. Such mixing is not included in the 1-D, Lagrangian code. We are presently beginning a computational effort with a 2-D Eulerian code. The status of this effort is discussed. Experimentally we have designed an apparatus that will permit us to test the role of different gases and pressures. This system is also in a planar geometry, but the plasma channel is doughnut shaped, permitting us to avoid edge effects associated with the planar rectangular geometry. The first experiments with this design are quite encouraging and the status of this effort is also discussed

  3. General Purpose Data-Driven Monitoring for Space Operations

    Science.gov (United States)

    Iverson, David L.; Martin, Rodney A.; Schwabacher, Mark A.; Spirkovska, Liljana; Taylor, William McCaa; Castle, Joseph P.; Mackey, Ryan M.

    2009-01-01

    As modern space propulsion and exploration systems improve in capability and efficiency, their designs are becoming increasingly sophisticated and complex. Determining the health state of these systems, using traditional parameter limit checking, model-based, or rule-based methods, is becoming more difficult as the number of sensors and component interactions grow. Data-driven monitoring techniques have been developed to address these issues by analyzing system operations data to automatically characterize normal system behavior. System health can be monitored by comparing real-time operating data with these nominal characterizations, providing detection of anomalous data signatures indicative of system faults or failures. The Inductive Monitoring System (IMS) is a data-driven system health monitoring software tool that has been successfully applied to several aerospace applications. IMS uses a data mining technique called clustering to analyze archived system data and characterize normal interactions between parameters. The scope of IMS based data-driven monitoring applications continues to expand with current development activities. Successful IMS deployment in the International Space Station (ISS) flight control room to monitor ISS attitude control systems has led to applications in other ISS flight control disciplines, such as thermal control. It has also generated interest in data-driven monitoring capability for Constellation, NASA's program to replace the Space Shuttle with new launch vehicles and spacecraft capable of returning astronauts to the moon, and then on to Mars. Several projects are currently underway to evaluate and mature the IMS technology and complementary tools for use in the Constellation program. These include an experiment on board the Air Force TacSat-3 satellite, and ground systems monitoring for NASA's Ares I-X and Ares I launch vehicles. The TacSat-3 Vehicle System Management (TVSM) project is a software experiment to integrate fault

  4. Diagnostic measurements related to laser driven inertial confinement fusion

    International Nuclear Information System (INIS)

    Campbell, D.E.

    1979-01-01

    Scientists at the Lawrence Livermore Laboratory have been conducting laser driven inertial confinement fusion experiments for over five years. The first proof of the thermonuclear burn came at the Janus target irradiation facility in the spring of 1975. Since that time three succeedingly higher energy facilities have been constructed at Livermore, Cyclops, Argus and Shiva, where increased fusion efficiency has been demonstrated. A new facility, called Nova, is now in the construction phase and we are hopeful that scientific break even (energy released compared to incident laser energy on target) will be demonstrated here in early 1980's. Projected progress of the Livermore program is shown

  5. Laser-driven polarized H/D sources and targets

    International Nuclear Information System (INIS)

    Clasie, B.; Crawford, C.; Dutta, D.; Gao, H.; Seely, J.; Xu, W.

    2005-01-01

    Traditionally, Atomic Beam Sources are used to produce targets of nuclear polarized hydrogen (H) or deuterium (D) for experiments using storage rings. Laser-Driven Sources (LDSs) offer a factor of 20-30 gain in the target thickness (however, with lower polarization) and may produce a higher overall figure of merit. The LDS is based on the technique of spin-exchange optical pumping where alkali vapor is polarized by absorbing circularly polarized laser photons. The H or D atoms are nuclear-polarized through spin-exchange collisions with the polarized alkali vapor and through subsequent hyperfine interactions during frequent H-H or D-D collisions

  6. Two-dimensional simulations of magnetically-driven instabilities

    International Nuclear Information System (INIS)

    Peterson, D.; Bowers, R.; Greene, A.E.; Brownell, J.

    1986-01-01

    A two-dimensional Eulerian MHD code is used to study the evolution of magnetically-driven instabilities in cylindrical geometry. The code incorporates an equation of state, resistivity, and radiative cooling model appropriate for an aluminum plasma. The simulations explore the effects of initial perturbations, electrical resistivity, and radiative cooling on the growth and saturation of the instabilities. Comparisons are made between the 2-D simulations, previous 1-D simulations, and results from the Pioneer experiments of the Los Alamos foil implosion program

  7. Research on accelerator-driven transmutation and studies of experimental facilities

    Energy Technology Data Exchange (ETDEWEB)

    Takizuka, Takakazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-11-01

    JAERI is carrying out R and Ds on accelerator-driven transmutation systems under the national OMEGA Program that aims at development of the technology to improve efficiency and safety in the final disposal of radioactive waste. Research facilities for accelerator-driven transmutation experiments are proposed to construct within the framework of the planned JAERI Neutron Science Project. This paper describes the features of the proposed accelerator-driven transmutation systems and their technical issues to be solved. A research facility plan under examination is presented. The plan is divided in two phases. In the second phase, technical feasibility of accelerator-driven systems will be demonstrated with a 30-60 MW experimental integrated system and with a 7 MW high-power target facility. (author)

  8. The Arizona Universities Library Consortium patron-driven e-book model

    Directory of Open Access Journals (Sweden)

    Jeanne Richardson

    2013-03-01

    Full Text Available Building on Arizona State University's patron-driven acquisitions (PDA initiative in 2009, the Arizona Universities Library Consortium, in partnership with the Ingram Content Group, created a cooperative patron-driven model to acquire electronic books (e-books. The model provides the opportunity for faculty and students at the universities governed by the Arizona Board of Regents (ABOR to access a core of e-books made accessible through resource discovery services and online catalogs. These books are available for significantly less than a single ABOR university would expend for the same materials. The patron-driven model described is one of many evolving models in digital scholarship, and, although the Arizona Universities Library Consortium reports a successful experience, patron-driven models pose questions to stakeholders in the academic publishing industry.

  9. LHC-GCS a model-driven approach for automatic PLC and SCADA code generation

    CERN Document Server

    Thomas, Geraldine; Barillère, Renaud; Cabaret, Sebastien; Kulman, Nikolay; Pons, Xavier; Rochez, Jacques

    2005-01-01

    The LHC experiments’ Gas Control System (LHC GCS) project [1] aims to provide the four LHC experiments (ALICE, ATLAS, CMS and LHCb) with control for their 23 gas systems. To ease the production and maintenance of 23 control systems, a model-driven approach has been adopted to generate automatically the code for the Programmable Logic Controllers (PLCs) and for the Supervision Control And Data Acquisition (SCADA) systems. The first milestones of the project have been achieved. The LHC GCS framework [4] and the generation tools have been produced. A first control application has actually been generated and is in production, and a second is in preparation. This paper describes the principle and the architecture of the model-driven solution. It will in particular detail how the model-driven solution fits with the LHC GCS framework and with the UNICOS [5] data-driven tools.

  10. Intense laser driven collision-less shock and ion acceleration in magnetized plasmas

    Science.gov (United States)

    Mima, K.; Jia, Q.; Cai, H. B.; Taguchi, T.; Nagatomo, H.; Sanz, J. R.; Honrubia, J.

    2016-05-01

    The generation of strong magnetic field with a laser driven coil has been demonstrated by many experiments. It is applicable to the magnetized fast ignition (MFI), the collision-less shock in the astrophysics and the ion shock acceleration. In this paper, the longitudinal magnetic field effect on the shock wave driven by the radiation pressure of an intense short pulse laser is investigated by theory and simulations. The transition of a laminar shock (electro static shock) to the turbulent shock (electromagnetic shock) occurs, when the external magnetic field is applied in near relativistic cut-off density plasmas. This transition leads to the enhancement of conversion of the laser energy into high energy ions. The enhancement of the conversion efficiency is important for the ion driven fast ignition and the laser driven neutron source. It is found that the total number of ions reflected by the shock increases by six time when the magnetic field is applied.

  11. Consistent data-driven computational mechanics

    Science.gov (United States)

    González, D.; Chinesta, F.; Cueto, E.

    2018-05-01

    We present a novel method, within the realm of data-driven computational mechanics, to obtain reliable and thermodynamically sound simulation from experimental data. We thus avoid the need to fit any phenomenological model in the construction of the simulation model. This kind of techniques opens unprecedented possibilities in the framework of data-driven application systems and, particularly, in the paradigm of industry 4.0.

  12. Comments to accelerator-driven system

    International Nuclear Information System (INIS)

    Taka aki, Matsumoto

    2003-01-01

    Accelerator-driven system (ADS) that was a subcritical nuclear reactor driven by a high power proton accelerator was recently studied by several large organisations over the world. This paper described two comments for ADS: philosophical and technological ones. The latter was made from a view point of micro ball lightning (BL) that was newly discovered by the author. Negative and positive aspects of micro BL for ADS were discussed. (author)

  13. Contribution to the experimental validation of the coupling between a particle accelerator and a subcritical core: Muse-3 and Muse-7 experiments; Contribution a la validation experimentale du couplage entre un accelerateur et un massif sous-critique: experience muse 3. et muse 4

    Energy Technology Data Exchange (ETDEWEB)

    Bompas, C A

    2000-12-01

    As part of the research on the Hybrid Systems and more specially on the physical phenomena involved in a sub-critical core coupled with an external source, it is necessary to qualify several neutronic parameters. These parameters characterize, on the one hand, the external source supplying the core with neutrons (importance, amplification) and, on the other hand, the sub-critical core (spatial distribution of flux, power emitted from the core, reactivity, influence of a spectrum degraded by the presence of buffers like lead). The MUSE Program consists of parametric studies of configuration with different compositions at different sub-critical levels supplied by different types of external source. The first part of this work concerns the first analyses of the static results obtained during the third phase of this experimental program (MUSE-III experiment) and also the preparation of the fourth phase (MUSE-IV experiment). This study has notably concluded on the superiority of a transition zone in lead compared to a sodium zone in terms of neutronic potential (because of the (n, 2n) reaction) and of the source importance. The second part of this work concerns the interpretation of the dynamic results obtained during the MUSE-III experiment and the realization of calculations on the MUSE-IV configurations. This study has shown the important impact of the hydrogenous materials on the external source for the MUSE-III dynamic results. It has also determined the applicability of the pulsed neutron source reactivity measurement technique and optimized the position of monitors for the future MUSE-IV experiment. (authors)

  14. A universal piezo-driven ultrasonic cell microinjection system.

    Science.gov (United States)

    Huang, Haibo; Mills, James K; Lu, Cong; Sun, Dong

    2011-08-01

    Over the past decade, the rapid development of biotechnologies such as gene injection, in-vitro fertilization, intracytoplasmic sperm injection (ICSI) and drug development have led to great demand for highly automated, high precision equipment for microinjection. Recently a new cell injection technology using piezo-driven pipettes with a very small mercury column was proposed and successfully applied in ICSI to a variety of mammal species. Although this technique significantly improves the survival rates of the ICSI process, shortcomings due to the toxicity of mercury and damage to the cell membrane due to large lateral tip oscillations of the injector pipette may limit its application. In this paper, a new cell injection system for automatic batch injection of suspended cells is developed. A new design of the piezo-driven cell injector is proposed for automated suspended cell injection. This new piezo-driven cell injector design relocates the piezo oscillation actuator to the injector pipette which eliminates the vibration effect on other parts of the micromanipulator. A small piezo stack is sufficient to perform the cell injection process. Harmful lateral tip oscillations of the injector pipette are reduced substantially without the use of a mercury column. Furthermore, ultrasonic vibration micro-dissection (UVM) theory is utilized to analyze the piezo-driven cell injection process, and the source of the lateral oscillations of the injector pipette is investigated. From preliminary experiments of cell injection of a large number of zebrafish embryos (n = 200), the injector pipette can easily pierce through the cell membrane at a low injection speed and almost no deformation of the cell wall, and with a high success rate(96%) and survival rate(80.7%) This new injection approach shows good potential for precision injection with less damage to the injected cells.

  15. Progress and prospects of ion-driven fast ignition

    International Nuclear Information System (INIS)

    Fernandez, Juan C.; Albright, Brian J.; Flippo, Kirk A.; Gautier, D. Cort; Hegelich, Bjoern M.; Schmitt, Mark J.; Yin Lin; Honrubia, J.J.; Temporal, M.

    2009-01-01

    Fusion fast ignition (FI) initiated by laser-driven ion beams is a promising concept examined in this paper. FI based on a beam of quasi-monoenergetic ions (protons or heavier ions) has the advantage of a more localized energy deposition, which minimizes the required total beam energy, bringing it close to the ∼10 kJ minimum required for fuel densities ∼500 g cm -3 . High-current, laser-driven ion beams are most promising for this purpose. Because they are born neutralized in picosecond timescales, these beams may deliver the power density required to ignite the compressed DT fuel, ∼10 kJ/10 ps into a spot 20 μm in diameter. Our modelling of ion-based FI include high fusion gain targets and a proof of principle experiment. That modelling indicates the concept is feasible, and provides confirmation of our understanding of the operative physics, a firmer foundation for the requirements, and a better understanding of the optimization trade space. An important benefit of the scheme is that such a high-energy, quasi-monoenergetic ignitor beam could be generated far from the capsule (≥1 cm away), eliminating the need for a reentrant cone in the capsule to protect the ion-generation laser target, a tremendous practical benefit. This paper summarizes the ion-based FI concept, the integrated ion-driven FI modelling, the requirements on the ignitor beam derived from that modelling, and the progress in developing a suitable laser-driven ignitor ion beam.

  16. Cygnus Performance in Subcritical Experiments

    International Nuclear Information System (INIS)

    G Corrow; M Hansen; D Henderson; S Lutz; C Mitton

    2008-01-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources with the following specifications: 4-rad dose at 1 m, 1-mm spot size, 50-ns pulse length, 2.25-MeV endpoint energy. The facility is located in an underground tunnel complex at the Nevada Test Site. Here SubCritical Experiments (SCEs) are performed to study the dynamic properties of plutonium. The Cygnus sources were developed as a primary diagnostic for these tests. Since SCEs are single-shot, high-value events - reliability and reproducibility are key issues. Enhanced reliability involves minimization of failure modes through design, inspection, and testing. Many unique hardware and operational features were incorporated into Cygnus to insure reliability. Enhanced reproducibility involves normalization of shot-to-shot output also through design, inspection, and testing. The first SCE to utilize Cygnus, Armando, was executed on May 25, 2004. A year later, April - May 2005, calibrations using a plutonium step wedge were performed. The results from this series were used for more precise interpretation of the Armando data. In the period February - May 2007 Cygnus was fielded on Thermos, which is a series of small-sample plutonium shots using a one-dimensional geometry. Pulsed power research generally dictates frequent change in hardware configuration. Conversely, SCE applications have typically required constant machine settings. Therefore, while operating during the past four years we have accumulated a large database for evaluation of machine performance under highly consistent operating conditions. Through analysis of this database Cygnus reliability and reproducibility on Armando, Step Wedge, and Thermos is presented

  17. Cygnus Performance in Subcritical Experiments

    Energy Technology Data Exchange (ETDEWEB)

    G. Corrow, M. Hansen, D. Henderson, S. Lutz, C. Mitton, et al.

    2008-02-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources with the following specifications: 4-rad dose at 1 m, 1-mm spot size, 50-ns pulse length, 2.25-MeV endpoint energy. The facility is located in an underground tunnel complex at the Nevada Test Site. Here SubCritical Experiments (SCEs) are performed to study the dynamic properties of plutonium. The Cygnus sources were developed as a primary diagnostic for these tests. Since SCEs are single-shot, high-value events - reliability and reproducibility are key issues. Enhanced reliability involves minimization of failure modes through design, inspection, and testing. Many unique hardware and operational features were incorporated into Cygnus to insure reliability. Enhanced reproducibility involves normalization of shot-to-shot output also through design, inspection, and testing. The first SCE to utilize Cygnus, Armando, was executed on May 25, 2004. A year later, April - May 2005, calibrations using a plutonium step wedge were performed. The results from this series were used for more precise interpretation of the Armando data. In the period February - May 2007 Cygnus was fielded on Thermos, which is a series of small-sample plutonium shots using a one-dimensional geometry. Pulsed power research generally dictates frequent change in hardware configuration. Conversely, SCE applications have typically required constant machine settings. Therefore, while operating during the past four years we have accumulated a large database for evaluation of machine performance under highly consistent operating conditions. Through analysis of this database Cygnus reliability and reproducibility on Armando, Step Wedge, and Thermos is presented.

  18. Accelerator driven reactors, - the significance of the energy distribution of spallation neutrons on the neutron statistics

    Energy Technology Data Exchange (ETDEWEB)

    Fhager, V

    2000-01-01

    In order to make correct predictions of the second moment of statistical nuclear variables, such as the number of fissions and the number of thermalized neutrons, the dependence of the energy distribution of the source particles on their number should be considered. It has been pointed out recently that neglecting this number dependence in accelerator driven systems might result in bad estimates of the second moment, and this paper contains qualitative and quantitative estimates of the size of these efforts. We walk towards the requested results in two steps. First, models of the number dependent energy distributions of the neutrons that are ejected in the spallation reactions are constructed, both by simple assumptions and by extracting energy distributions of spallation neutrons from a high-energy particle transport code. Then, the second moment of nuclear variables in a sub-critical reactor, into which spallation neutrons are injected, is calculated. The results from second moment calculations using number dependent energy distributions for the source neutrons are compared to those where only the average energy distribution is used. Two physical models are employed to simulate the neutron transport in the reactor. One is analytical, treating only slowing down of neutrons by elastic scattering in the core material. For this model, equations are written down and solved for the second moment of thermalized neutrons that include the distribution of energy of the spallation neutrons. The other model utilizes Monte Carlo methods for tracking the source neutrons as they travel inside the reactor material. Fast and thermal fission reactions are considered, as well as neutron capture and elastic scattering, and the second moment of the number of fissions, the number of neutrons that leaked out of the system, etc. are calculated. Both models use a cylindrical core with a homogenous mixture of core material. Our results indicate that the number dependence of the energy

  19. Accelerator driven reactors, - the significance of the energy distribution of spallation neutrons on the neutron statistics

    International Nuclear Information System (INIS)

    Fhager, V.

    2000-01-01

    In order to make correct predictions of the second moment of statistical nuclear variables, such as the number of fissions and the number of thermalized neutrons, the dependence of the energy distribution of the source particles on their number should be considered. It has been pointed out recently that neglecting this number dependence in accelerator driven systems might result in bad estimates of the second moment, and this paper contains qualitative and quantitative estimates of the size of these efforts. We walk towards the requested results in two steps. First, models of the number dependent energy distributions of the neutrons that are ejected in the spallation reactions are constructed, both by simple assumptions and by extracting energy distributions of spallation neutrons from a high-energy particle transport code. Then, the second moment of nuclear variables in a sub-critical reactor, into which spallation neutrons are injected, is calculated. The results from second moment calculations using number dependent energy distributions for the source neutrons are compared to those where only the average energy distribution is used. Two physical models are employed to simulate the neutron transport in the reactor. One is analytical, treating only slowing down of neutrons by elastic scattering in the core material. For this model, equations are written down and solved for the second moment of thermalized neutrons that include the distribution of energy of the spallation neutrons. The other model utilizes Monte Carlo methods for tracking the source neutrons as they travel inside the reactor material. Fast and thermal fission reactions are considered, as well as neutron capture and elastic scattering, and the second moment of the number of fissions, the number of neutrons that leaked out of the system, etc. are calculated. Both models use a cylindrical core with a homogenous mixture of core material. Our results indicate that the number dependence of the energy

  20. Accelerator Driven Systems (ADS) and transmutation of nuclear waste: Options and trends

    International Nuclear Information System (INIS)

    Stanculescu, A.

    2001-01-01

    The scope of the lecture is to present: 1) the rationale for transmutation, 2) the principle of ADS (spallation source, sub-critical blanket), 3) an overview of the main concepts being investigated and the ongoing R and D activities in this area, 4) development trends for this technology. (author)

  1. The interaction between stimulus-driven and goal-driven orienting as revealed by eye movements

    NARCIS (Netherlands)

    Schreij, D.B.B.; Los, S.A.; Theeuwes, J.; Enns, J.T.; Olivers, C.N.L.

    2014-01-01

    It is generally agreed that attention can be captured in a stimulus-driven or in a goal-driven fashion. In studies that investigated both types of capture, the effects on mean manual response time (reaction time [RT]) are generally additive, suggesting two independent underlying processes. However,

  2. System and safety studies of accelerator driven transmutation systems

    International Nuclear Information System (INIS)

    Gudowski, W.; Wallenius, J.; Tucek, K.; Eriksson, Marcus; Carlsson, Johan; Seltborg, P.; Cetnar, J.

    2001-05-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the department has been focused on: a) ADS core design and development of advanced nuclear fuel optimised for high transmutation rates and good safety features; b) analysis of ADS-dynamics c) computer code and nuclear data development relevant for simulation and optimization of ADS; d) participation in ADS experiments including 1 MW spallation target manufacturing, subcritical experiments MUSE (CEA-Cadarache). Moreover, during the reporting period the EU-project 'IABAT', co-ordinated by the department has been finished and 4 other projects have been initiated in the frame of the 5th European Framework Programme. Most of the research topics reported in this paper are referred to appendices, which have been published in the open literature. The topics, which are not yet published, are described here in more details

  3. System and safety studies of accelerator driven transmutation systems

    Energy Technology Data Exchange (ETDEWEB)

    Gudowski, W.; Wallenius, J.; Tucek, K.; Eriksson, Marcus; Carlsson, Johan; Seltborg, P.; Cetnar, J. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Nuclear and Reactor Physics

    2001-05-01

    The research on safety of Accelerator-Driven Transmutation Systems (ADS) at the department has been focused on: a) ADS core design and development of advanced nuclear fuel optimised for high transmutation rates and good safety features; b) analysis of ADS-dynamics c) computer code and nuclear data development relevant for simulation and optimization of ADS; d) participation in ADS experiments including 1 MW spallation target manufacturing, subcritical experiments MUSE (CEA-Cadarache). Moreover, during the reporting period the EU-project 'IABAT', co-ordinated by the department has been finished and 4 other projects have been initiated in the frame of the 5th European Framework Programme. Most of the research topics reported in this paper are referred to appendices, which have been published in the open literature. The topics, which are not yet published, are described here in more details.

  4. 252Cf-source-driven neutron noise analysis method

    International Nuclear Information System (INIS)

    Mihalczo, J.T.; King, W.T.; Blakeman, E.D.

    1985-01-01

    The 252 Cf-source-driven neutron noise analysis method has been tested in a a wide variety of experiments that have indicated the broad range of applicability of the method. The neutron multiplication factor, k/sub eff/ has been satisfactorily determined for a variety of materials including uranium metal, light water reactor fuel pins, fissile solutions, fuel plates in water, and interacting cylinders. For a uranyl nitrate solution tank which is typical of a fuel processing or reprocessing plant, the k/sub eff/ values were satisfactorily determined for values between 0.92 and 0.5 using a simple point kinetics interpretation of the experimental data. The short measurement times, in several cases as low as 1 min, have shown that the development of this method can lead to a practical subcriticality monitor for many in-plant applications. The further development of the method will require experiments and the development of theoretical methods to predict the experimental observables

  5. Fluid-Driven Deformation of a Soft Porous Medium

    Science.gov (United States)

    Lutz, Tyler; Wilen, Larry; Wettlaufer, John

    2017-11-01

    Viscous drag forces resisting the flow of fluid through a soft porous medium are maintained by restoring forces associated with deformations in the solid matrix. We describe experimental measurements of the deformation of foam under a pressure-driven flow of water along a single axis. Image analysis techniques allow tracking of the foam displacement while pressure sensors allow measurement of the fluid pressure. Experiments are performed for a series of different pressure heads ranging from 10 to 90 psi, and the results are compared to theory. This work builds on previous measurements of the fluid-induced deformation of a bed of soft hydrogel spheres. Compared to the hydrogel system, foams have the advantage that the constituents of the porous medium do not rearrange during an experiment, but they have the disadvantage of having a high friction coefficient with any boundaries. We detail strategies to characterize and mitigate the effects of friction on the observed foam deformations.

  6. Spreading of wave-driven currents in a tokamak

    International Nuclear Information System (INIS)

    Ignat, D.W.; Kaita, R.; Jardin, S.C.; Okabayashi, M.

    1996-01-01

    Lower hybrid current drive (LHCD) in the tokamak Princeton Beta Experiment-Modification (PBX-M) is computed with a dynamic model in order to understand an actual discharge aimed at raising the central q above unity. Such configurations offer advantages for steady-state operation and plasma stability. For the particular parameters of this PBX-M experiment, the calculation found singular profiles of plasma current density J and safety factor q developing soon after LHCD begins. Smoothing the lower hybrid-driven current and power using a diffusion-Eke equation and a velocity-independent diffusivity for fast-electron current brought the model into reasonable agreement with the measurements if D fast ∼ 1.0 m 2 /s. Such a value for D fast is in the range suggested by other work

  7. Electrothermal instability growth in magnetically driven pulsed power liners

    International Nuclear Information System (INIS)

    Peterson, Kyle J.; Sinars, Daniel B.; Yu, Edmund P.; Herrmann, Mark C.; Cuneo, Michael E.; Slutz, Stephen A.; Smith, Ian C.; Atherton, Briggs W.; Knudson, Marcus D.; Nakhleh, Charles

    2012-01-01

    This paper explores the role of electro-thermal instabilities on the dynamics of magnetically accelerated implosion systems. Electro-thermal instabilities result from non-uniform heating due to temperature dependence in the conductivity of a material. Comparatively little is known about these types of instabilities compared to the well known Magneto-Rayleigh-Taylor (MRT) instability. We present simulations that show electrothermal instabilities form immediately after the surface material of a conductor melts and can act as a significant seed to subsequent MRT instability growth. We also present the results of several experiments performed on Sandia National Laboratories Z accelerator to investigate signatures of electrothermal instability growth on well characterized initially solid aluminum and copper rods driven with a 20 MA, 100 ns risetime current pulse. These experiments show excellent agreement with electrothermal instability simulations and exhibit larger instability growth than can be explained by MRT theory alone.

  8. Selection of initial events of accelerator driven subcritical system

    International Nuclear Information System (INIS)

    Wang Qianglong; Hu Liqin; Wang Jiaqun; Li Yazhou; Yang Zhiyi

    2013-01-01

    The Probabilistic Safety Assessment (PSA) is an important tool in reactor safety analysis and a significant reference to the design and operation of reactor. It is the origin and foundation of the PSA for a reactor to select the initial events. Accelerator Driven Subcritical System (ADS) has advanced design characteristics, complicated subsystems and little engineering and operating experience, which makes it much more difficult to identify the initial events of ADS. Based on the current design project of ADS, the system's safety characteristics and special issues were analyzed in this article. After a series of deductions with Master Logic Diagram (MLD) and considering the relating experience of other advanced research reactors, a preliminary initial events was listed finally, which provided the foundation for the next safety assessment. (authors)

  9. Diagnostics for pellet experiments

    International Nuclear Information System (INIS)

    Johnson, R.R.

    1978-01-01

    The target diagnostics which are being used and planned in current laser driven ICF Experiments are described. Most of these diagnostics can be easily applied to future ion-beam fusion experiments. The status of laser fusion diagnostics has been much improved in the last 5 years and further improvements can be expected and should be available when the first ICF experiments using ion beams are performed. As an example, x-ray temporal and spatial resolutions are now approximately 5 psec and 3 μm, which is approximately a factor of 4 better than the resolution reported in the first implosion experiments. As one plans ahead for ion-beam fusion experiments it should be emphasized that high yield experiments are easier to diagnose provided adequate shielding is employed. However, in the event that the first high yield experiments fail it will be necessary to have diagnostics available to determine where the problems lie. In laser fusion it is interesting to note that higher laser powers are required now for breakeven experiments than first anticipated, mainly because some aspects of the laser-interaction physics were not recognized until the experiments were carefully diagnosed. Thus as has been pointed out, it may be necessary to increase the energy of the ion-beam driver to enable us to do breakeven experiments with high confidence

  10. Science-Driven Computing: NERSC's Plan for 2006-2010

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Horst D.; Kramer, William T.C.; Bailey, David H.; Banda,Michael J.; Bethel, E. Wes; Craw, James M.; Fortney, William J.; Hules,John A.; Meyer, Nancy L.; Meza, Juan C.; Ng, Esmond G.; Rippe, Lynn E.; Saphir, William C.; Verdier, Francesca; Walter, Howard A.; Yelick,Katherine A.

    2005-05-16

    NERSC has developed a five-year strategic plan focusing on three components: Science-Driven Systems, Science-Driven Services, and Science-Driven Analytics. (1) Science-Driven Systems: Balanced introduction of the best new technologies for complete computational systems--computing, storage, networking, visualization and analysis--coupled with the activities necessary to engage vendors in addressing the DOE computational science requirements in their future roadmaps. (2) Science-Driven Services: The entire range of support activities, from high-quality operations and user services to direct scientific support, that enable a broad range of scientists to effectively use NERSC systems in their research. NERSC will concentrate on resources needed to realize the promise of the new highly scalable architectures for scientific discovery in multidisciplinary computational science projects. (3) Science-Driven Analytics: The architectural and systems enhancements and services required to integrate NERSC's powerful computational and storage resources to provide scientists with new tools to effectively manipulate, visualize, and analyze the huge data sets derived from simulations and experiments.

  11. Molecular dynamics for irradiation driven chemistry

    DEFF Research Database (Denmark)

    Sushko, Gennady B.; Solov'yov, Ilia A.; Solov'yov, Andrey V.

    2016-01-01

    A new molecular dynamics (MD) approach for computer simulations of irradiation driven chemical transformations of complex molecular systems is suggested. The approach is based on the fact that irradiation induced quantum transformations can often be treated as random, fast and local processes...... that describe the classical MD of complex molecular systems under irradiation. The proposed irradiation driven molecular dynamics (IDMD) methodology is designed for the molecular level description of the irradiation driven chemistry. The IDMD approach is implemented into the MBN Explorer software package...... involving small molecules or molecular fragments. We advocate that the quantum transformations, such as molecular bond breaks, creation and annihilation of dangling bonds, electronic charge redistributions, changes in molecular topologies, etc., could be incorporated locally into the molecular force fields...

  12. Taylor dispersion in wind-driven current

    Science.gov (United States)

    Li, Gang; Wang, Ping; Jiang, Wei-Quan; Zeng, Li; Li, Zhi; Chen, G. Q.

    2017-12-01

    Taylor dispersion associated with wind-driven currents in channels, shallow lakes and estuaries is essential to hydrological environmental management. For solute dispersion in a wind-driven current, presented in this paper is an analytical study of the evolution of concentration distribution. The concentration moments are intensively derived for an accurate presentation of the mean concentration distribution, up to the effect of kurtosis. The vertical divergence of concentration is then deduced by Gill's method of series expansion up to the fourth order. Based on the temporal evolution of the vertical concentration distribution, the dispersion process in the wind-driven current is concretely characterized. The uniform shear leads to a special symmetrical distribution of mean concentration free of skewness. The non-uniformity of vertical concentration is caused by convection and smeared out gradually by the effect of diffusion, but fails to disappear even at large times.

  13. Test-driven modeling of embedded systems

    DEFF Research Database (Denmark)

    Munck, Allan; Madsen, Jan

    2015-01-01

    To benefit maximally from model-based systems engineering (MBSE) trustworthy high quality models are required. From the software disciplines it is known that test-driven development (TDD) can significantly increase the quality of the products. Using a test-driven approach with MBSE may have...... a similar positive effect on the quality of the system models and the resulting products and may therefore be desirable. To define a test-driven model-based systems engineering (TD-MBSE) approach, we must define this approach for numerous sub disciplines such as modeling of requirements, use cases...... suggest that our method provides a sound foundation for rapid development of high quality system models....

  14. Semantic Web and Model-Driven Engineering

    CERN Document Server

    Parreiras, Fernando S

    2012-01-01

    The next enterprise computing era will rely on the synergy between both technologies: semantic web and model-driven software development (MDSD). The semantic web organizes system knowledge in conceptual domains according to its meaning. It addresses various enterprise computing needs by identifying, abstracting and rationalizing commonalities, and checking for inconsistencies across system specifications. On the other side, model-driven software development is closing the gap among business requirements, designs and executables by using domain-specific languages with custom-built syntax and se

  15. Measurement of beam driven hydrodynamic turbulence

    International Nuclear Information System (INIS)

    Norem, J.; Black, E.; Bandura, L.; Errede, D.; Cummings, M. A. C.

    2003-01-01

    Cooling intense muon beams in liquid hydrogen absorbers introduces kW of heating to the cold fluid, which will drive turbulent flow. The amount of turbulence may be sufficient to help cool the liquid, but calculations are difficult. We have used a 20 MeV electron beam in a water tank to look at the scale of the beam driven convection and turbulence. The density and flow measurements are made with schlieren and Ronchi systems. We describe the optical systems and the turbulence measured. These data are being used to calibrate hydrodynamic calculations of convection driven and forced flow cooling in muon cooling absorbers

  16. User-driven innovation in tourism

    DEFF Research Database (Denmark)

    Hjalager, Anne-Mette; Nordin, Sara

    2011-01-01

    This literature study reviews user-driven innovation and establishes a typology of its forms in a tourism context. Sixteen methods are distinguishable. They comprise situations where users are actively involved and methods where information is collected without direct user involvement. The nature...... and intensity of the dialogue between companies and their customers are addressed. Drawing on this existing research, the article concludes that there is still little comprehensive follow-up on user-driven innovation in tourism and its impact on quality improvements and assurance. Key areas for future studies...

  17. Statistical Transmutation in Floquet Driven Optical Lattices.

    Science.gov (United States)

    Sedrakyan, Tigran A; Galitski, Victor M; Kamenev, Alex

    2015-11-06

    We show that interacting bosons in a periodically driven two dimensional (2D) optical lattice may effectively exhibit fermionic statistics. The phenomenon is similar to the celebrated Tonks-Girardeau regime in 1D. The Floquet band of a driven lattice develops the moat shape, i.e., a minimum along a closed contour in the Brillouin zone. Such degeneracy of the kinetic energy favors fermionic quasiparticles. The statistical transmutation is achieved by the Chern-Simons flux attachment similar to the fractional quantum Hall case. We show that the velocity distribution of the released bosons is a sensitive probe of the fermionic nature of their stationary Floquet state.

  18. Investigation toward laser driven IFE power plant

    International Nuclear Information System (INIS)

    Nakai, S.; Kozaki, Y.; Izawa, Y.

    2001-01-01

    Inertial fusion energy (IFE) is becoming feasible due to the increasing understanding of implosion physics. Reactor technology issues have begun to be developed. Based on the conceptual design of Laser Driven IFE Power Plant, the technical and physical issues have been examined. R and D on key issues that affect the feasibility of power plant have been proceeded taking into account the collaboration in the field of laser driver, fuel pellet, reaction chamber and system design. It is concluded that the technical feasibility of IFE power plant seems to be reasonably high. Coordination and collaboration scheme of reactor technology experts in Japan on Laser Driven IFE Power Plant is being proceeded. (author)

  19. An experimental and analytical study of a buoyancy driven cooling system for a particle accelerator

    International Nuclear Information System (INIS)

    Campbell, B.; Ranganathan, R.

    1993-05-01

    A buoyancy driven closed-loop cooling system that transports the heat generated in a particle accelerator to the ambient has been evaluated both through experiments performed earlier and analysis techniques developed elsewhere. Excellent comparisons between measurements and calculations have been obtained. The model illustrates the feasibility (from a heat transfer viewpoint) of such a cooling system for a particle accelerator

  20. An experimental and analytical study of a buoyancy driven cooling system for a particle accelerator

    International Nuclear Information System (INIS)

    Campbell, B.; Ranganathan, R.

    1993-01-01

    A buoyancy driven closed-loop cooling system that transports the heat generated in a particle accelerator to the ambient has been evaluated both through experiments performed earlier and analysis techniques developed elsewhere. Excellent comparisons between measurements and calculations have been obtained. The model illustrates the feasibility (from a heat transfer viewpoint) of such a cooling system for a particle accelerator

  1. LIF-measurements on a low prassure RF-driven InBr lamp

    NARCIS (Netherlands)

    Mulders, H.C.J.; Stoffels, W.W.

    2007-01-01

    A laser induced fluorescence (LIF) experiment has been carried out on a low pressure, capacitively coupled RF driven. Ar discharge with InBr as an additive. The intention is to find the density of the different states of InBr and the metastable states in particular. We measured the density profile

  2. Supervising nursing students in a technology-driven medication administration process in a hospital setting

    DEFF Research Database (Denmark)

    Gaard, Mette; Orbæk, Janne

    2016-01-01

    REVIEW QUESTION/OBJECTIVE: The objective of this review is to identify, describe and synthesize the experiences of nurse supervisors and the factors that influence the supervision of pre-graduate nursing students in undertaking technology-driven medication administration in hospital settings...

  3. Writing through Big Data: New Challenges and Possibilities for Data-Driven Arguments

    Science.gov (United States)

    Beveridge, Aaron

    2017-01-01

    As multimodal writing continues to shift and expand in the era of Big Data, writing studies must confront the new challenges and possibilities emerging from data mining, data visualization, and data-driven arguments. Often collected under the broad banner of "data literacy," students' experiences of data visualization and data-driven…

  4. Heat Flux of a Transferred Arc Driven by a Transverse Magnetic Field

    Directory of Open Access Journals (Sweden)

    Naomi Matsumoto

    2009-01-01

    Full Text Available Theoretical consideration of a magnetically driven arc was performed to elucidate the variation of heat flux with an imposed DC magnetic field. Experiments were conducted to confirm the validity of the theoretical model. The heat flux decreased concomitantly with increased imposed magnetic flux density. Theoretical predictions agreed with experimental results.

  5. Dictionary-driven protein annotation.

    Science.gov (United States)

    Rigoutsos, Isidore; Huynh, Tien; Floratos, Aris; Parida, Laxmi; Platt, Daniel

    2002-09-01

    released publicly after we built the Bio-Dictionary that is used in our experiments. Finally, we have computed the annotations of more than 70 complete genomes and made them available on the World Wide Web at http://cbcsrv.watson.ibm.com/Annotations/.

  6. Nonequilibrium steady states and resonant tunneling in time-periodically driven systems with interactions

    Science.gov (United States)

    Qin, Tao; Hofstetter, Walter

    2018-03-01

    Time-periodically driven systems are a versatile toolbox for realizing interesting effective Hamiltonians. Heating, caused by excitations to high-energy states, is a challenge for experiments. While most setups so far address the relatively weakly interacting regime, it is of general interest to study heating in strongly correlated systems. Using Floquet dynamical mean-field theory, we study nonequilibrium steady states (NESS) in the Falicov-Kimball model, with time-periodically driven kinetic energy or interaction. We systematically investigate the nonequilibrium properties of the NESS. For a driven kinetic energy, we show that resonant tunneling, where the interaction is an integer multiple of the driving frequency, plays an important role in the heating. In the strongly correlated regime, we show that this can be well understood using Fermi's golden rule and the Schrieffer-Wolff transformation for a time-periodically driven system. We furthermore demonstrate that resonant tunneling can be used to control the population of Floquet states to achieve "photodoping." For driven interactions introduced by an oscillating magnetic field near a widely adopted Feshbach resonance, we find that the double occupancy is strongly modulated. Our calculations apply to shaken ultracold-atom systems and to solid-state systems in a spatially uniform but time-dependent electric field. They are also closely related to lattice modulation spectroscopy. Our calculations are helpful to understand the latest experiments on strongly correlated Floquet systems.

  7. Summary Report of Working Group 5: Electron Beam Driven Plasma Accelerators

    International Nuclear Information System (INIS)

    Hogan, Mark J.; Conde, Manoel E.

    2009-01-01

    Electron beam driven plasma accelerators have seen rapid progress over the last decade. Recent efforts have built on this success by constructing a concept for a plasma wakefield accelerator based linear collider. The needs for any future collider to deliver both energy and luminosity have substantial implications for interpreting current experiments and setting priorities for the future. This working group reviewed current experiments and ideas in the context of the demands of a future collider. The many discussions and presentations are summarized here.

  8. Manuscript 101: A Data-Driven Writing Exercise For Beginning Scientists

    OpenAIRE

    Ralston, Amy; Halbisen, Michael

    2017-01-01

    Learning to write a scientific manuscript is one of the most important and rewarding scientific training experiences, yet most young scientists only embark on this experience relatively late in graduate school, after gathering sufficient data in the lab. Yet, familiarity with the process of writing a scientific manuscript and receiving peer reviews, often leads to a more focused and driven experimental approach. To jump-start this training, we developed a protocol for teaching manuscript writ...

  9. Requirements of a proton beam accelerator for an accelerator-driven reactor

    International Nuclear Information System (INIS)

    Takahashi, H.; Zhao, Y.; Tsoupas, N.; An, Y.; Yamazaki, Y.

    1997-01-01

    When the authors first proposed an accelerator-driven reactor, the concept was opposed by physicists who had earlier used the accelerator for their physics experiments. This opposition arose because they had nuisance experiences in that the accelerator was not reliable, and very often disrupted their work as the accelerator shut down due to electric tripping. This paper discusses the requirements for the proton beam accelerator. It addresses how to solve the tripping problem and how to shape the proton beam

  10. Construction and characterization of a laser-driven proton beamline at GSI

    OpenAIRE

    Busold, Simon

    2014-01-01

    The thesis includes the first experiments with the new 100 TW laser beamline of the PHELIX laser facility at GSI Darmstadt to drive a TNSA (Target Normal Sheath Acceleration) proton source at GSI's Z6 experimental area. At consecutive stages a pulsed solenoid has been applied for beam transport and energy selection via chromatic focusing, as well as a radiofrequency cavity for energy compression of the bunch. This novel laser-driven proton beamline, representing a central experiment of the...

  11. The User-Driven Creative Academy

    DEFF Research Database (Denmark)

    Nielsen, Louise Møller; Poulsen, Søren Bolvig

    2016-01-01

    Users have always been a point of focus in design, but in the beginning of the new millennium userdriven approaches and user-oriented projects were taken to a new level of recognition. As part of this development, the User Driven Creative Academy (U-CrAc) was created at Aalborg University...

  12. Direct Numerical Simulation of Driven Cavity Flows

    NARCIS (Netherlands)

    Verstappen, R.; Wissink, J.G.; Veldman, A.E.P.

    Direct numerical simulations of 2D driven cavity flows have been performed. The simulations exhibit that the flow converges to a periodically oscillating state at Re=11,000, and reveal that the dynamics is chaotic at Re=22,000. The dimension of the attractor and the Kolmogorov entropy have been

  13. Mastering Technologies in Design-Driven Innovation

    DEFF Research Database (Denmark)

    Dell'era, Claudio; Marchesi, Alessio; Verganti, Roberto

    2010-01-01

    Only a few companies have mastered the design-driven approach to innovation. This paper examines what it means to make design a central part of the business process, able to add value to products and create new markets. More specifically, it focuses on the interplay between the functional and sem...

  14. Data-driven regionalization of housing markets

    NARCIS (Netherlands)

    Helbich, M.; Brunauer, W.; Hagenauer, J.; Leitner, M.

    2013-01-01

    This article presents a data-driven framework for housing market segmentation. Local marginal house price surfaces are investigated by means of mixed geographically weighted regression and are reduced to a set of principal component maps, which in turn serve as input for spatial regionalization. The

  15. Functionality-driven fractionation of lupin seeds

    NARCIS (Netherlands)

    Berghout, J.A.M.

    2015-01-01

    Functionality-driven fractionation of lupin seeds

    The growth in the world population requires an increase in the production of protein-rich foods from plant-based materials. Lupin seeds have potential to become a novel plant protein source for food products because they are rich

  16. Quantitative system validation in model driven design

    DEFF Research Database (Denmark)

    Hermanns, Hilger; Larsen, Kim Guldstrand; Raskin, Jean-Francois

    2010-01-01

    The European STREP project Quasimodo1 develops theory, techniques and tool components for handling quantitative constraints in model-driven development of real-time embedded systems, covering in particular real-time, hybrid and stochastic aspects. This tutorial highlights the advances made, focus...

  17. Failure-probability driven dose painting

    DEFF Research Database (Denmark)

    Vogelius, Ivan R; Håkansson, Katrin; Due, Anne K

    2013-01-01

    To demonstrate a data-driven dose-painting strategy based on the spatial distribution of recurrences in previously treated patients. The result is a quantitative way to define a dose prescription function, optimizing the predicted local control at constant treatment intensity. A dose planning study...

  18. High-explosive driven crowbar switch

    International Nuclear Information System (INIS)

    Dike, R.S.; Kewish, R.W. Jr.

    1976-01-01

    The disclosure relates to a compact explosive driven switch for use as a low resistance, low inductance crowbar switch. A high-explosive charge extrudes a deformable conductive metallic plate through a polyethylene insulating layer to achieve a hard current contact with a supportive annular conductor

  19. Data Driven Constraints for the SVM

    DEFF Research Database (Denmark)

    Darkner, Sune; Clemmensen, Line Katrine Harder

    2012-01-01

    We propose a generalized data driven constraint for support vector machines exemplified by classification of paired observations in general and specifically on the human ear canal. This is particularly interesting in dynamic cases such as tissue movement or pathologies developing over time. Assum...

  20. Light-driven robotics for nanoscopy

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    2013-01-01

    The science fiction inspired shrinking of macro-scale robotic manipulation and handling down to the micro- and nanoscale regime opens new doors for exploiting the forces and torques of light for micro- and nanoscopic probing, actuation and control. Advancing light-driven micro-robotics requires...... and matter for robotically probing at the smallest biological length scales....